diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 0000000..1ad899d
Binary files /dev/null and b/.DS_Store differ
diff --git a/Gemfile b/Gemfile
index 2202551..7514cd5 100644
--- a/Gemfile
+++ b/Gemfile
@@ -15,19 +15,23 @@ gemspec
 
 ruby '2.5.8'
 
-gem 'dotenv-rails', require: 'dotenv/rails-now'
+gem 'dotenv-rails', '~> 2.7', require: 'dotenv/rails-now'
 # gem 'jquery-rails'
 gem 'puma'
 gem 'pg', '0.20'
 gem 'rails_12factor', group: :production
-gem 'devise', '>= 4.6.0'
+gem 'devise', '~> 4.7'
 
 group :test do
-  gem 'rspec-rails'
-  gem 'cucumber-rails', '~> 1.4.4', require: false
+  gem 'rspec-rails', '~> 4.0.1'
+  gem 'cucumber-rails', '~> 2.1', require: false
   gem 'factory_bot_rails'
   gem 'database_cleaner'
   gem 'stripe-ruby-mock', '~> 2.5.2', require: 'stripe_mock'
   gem 'poltergeist'
-  gem "codeclimate-test-reporter", require: nil
+  gem 'codeclimate-test-reporter', require: nil
+
+  # assigns is deprecated - TODO: move to request specs
+  # see https://stackoverflow.com/questions/42001517/rspec-rails-controller-testing-with-assertions-and-assigns
+  gem 'rails-controller-testing' 
 end
\ No newline at end of file
diff --git a/Gemfile.lock b/Gemfile.lock
index 534785c..b8cd74b 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -8,7 +8,7 @@ PATH
       jquery-rails (~> 4.2)
       mini_racer (~> 0.3)
       paper_trail (~> 4.2)
-      rails (~> 4.2)
+      rails (~> 5.2)
       rails-assets-tether (>= 1.1)
       sass-rails (~> 5.0)
       stripe (~> 3.9)
@@ -21,46 +21,52 @@ GEM
   specs:
     aasm (4.12.3)
       concurrent-ruby (~> 1.0)
-    actionmailer (4.2.11)
-      actionpack (= 4.2.11)
-      actionview (= 4.2.11)
-      activejob (= 4.2.11)
+    actioncable (5.2.4.3)
+      actionpack (= 5.2.4.3)
+      nio4r (~> 2.0)
+      websocket-driver (>= 0.6.1)
+    actionmailer (5.2.4.3)
+      actionpack (= 5.2.4.3)
+      actionview (= 5.2.4.3)
+      activejob (= 5.2.4.3)
       mail (~> 2.5, >= 2.5.4)
-      rails-dom-testing (~> 1.0, >= 1.0.5)
-    actionpack (4.2.11)
-      actionview (= 4.2.11)
-      activesupport (= 4.2.11)
-      rack (~> 1.6)
-      rack-test (~> 0.6.2)
-      rails-dom-testing (~> 1.0, >= 1.0.5)
+      rails-dom-testing (~> 2.0)
+    actionpack (5.2.4.3)
+      actionview (= 5.2.4.3)
+      activesupport (= 5.2.4.3)
+      rack (~> 2.0, >= 2.0.8)
+      rack-test (>= 0.6.3)
+      rails-dom-testing (~> 2.0)
       rails-html-sanitizer (~> 1.0, >= 1.0.2)
-    actionview (4.2.11)
-      activesupport (= 4.2.11)
+    actionview (5.2.4.3)
+      activesupport (= 5.2.4.3)
       builder (~> 3.1)
-      erubis (~> 2.7.0)
-      rails-dom-testing (~> 1.0, >= 1.0.5)
+      erubi (~> 1.4)
+      rails-dom-testing (~> 2.0)
       rails-html-sanitizer (~> 1.0, >= 1.0.3)
-    activejob (4.2.11)
-      activesupport (= 4.2.11)
-      globalid (>= 0.3.0)
-    activemodel (4.2.11)
-      activesupport (= 4.2.11)
-      builder (~> 3.1)
-    activerecord (4.2.11)
-      activemodel (= 4.2.11)
-      activesupport (= 4.2.11)
-      arel (~> 6.0)
-    activesupport (4.2.11)
-      i18n (~> 0.7)
+    activejob (5.2.4.3)
+      activesupport (= 5.2.4.3)
+      globalid (>= 0.3.6)
+    activemodel (5.2.4.3)
+      activesupport (= 5.2.4.3)
+    activerecord (5.2.4.3)
+      activemodel (= 5.2.4.3)
+      activesupport (= 5.2.4.3)
+      arel (>= 9.0)
+    activestorage (5.2.4.3)
+      actionpack (= 5.2.4.3)
+      activerecord (= 5.2.4.3)
+      marcel (~> 0.3.1)
+    activesupport (5.2.4.3)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 0.7, < 2)
       minitest (~> 5.1)
-      thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
     addressable (2.5.2)
       public_suffix (>= 2.0.2, < 4.0)
-    arel (6.0.4)
+    arel (9.0.0)
     autoprefixer-rails (9.8.6.3)
       execjs
-    backports (3.11.1)
     bcrypt (3.1.13)
     bootstrap (4.5.2)
       autoprefixer-rails (>= 9.1.0)
@@ -87,32 +93,47 @@ GEM
       coffee-script-source
       execjs
     coffee-script-source (1.12.2)
-    concurrent-ruby (1.1.6)
+    concurrent-ruby (1.1.7)
     crass (1.0.6)
-    cucumber (3.1.0)
-      builder (>= 2.1.2)
-      cucumber-core (~> 3.1.0)
-      cucumber-expressions (~> 5.0.4)
-      cucumber-wire (~> 0.0.1)
-      diff-lcs (~> 1.3)
-      gherkin (~> 5.0)
-      multi_json (>= 1.7.5, < 2.0)
-      multi_test (>= 0.1.2)
-    cucumber-core (3.1.0)
-      backports (>= 3.8.0)
-      cucumber-tag_expressions (~> 1.1.0)
-      gherkin (>= 5.0.0)
-    cucumber-expressions (5.0.13)
-    cucumber-rails (1.4.5)
-      capybara (>= 1.1.2, < 3)
-      cucumber (>= 1.3.8, < 4)
-      mime-types (>= 1.16, < 4)
-      nokogiri (~> 1.5)
-      railties (>= 3, < 5.1)
-    cucumber-tag_expressions (1.1.1)
-    cucumber-wire (0.0.1)
+    cucumber (4.1.0)
+      builder (~> 3.2, >= 3.2.3)
+      cucumber-core (~> 7.1, >= 7.1.0)
+      cucumber-create-meta (~> 1.0.0, >= 1.0.0)
+      cucumber-cucumber-expressions (~> 10.1, >= 10.1.0)
+      cucumber-gherkin (~> 14.0, >= 14.0.1)
+      cucumber-html-formatter (~> 7.0, >= 7.0.0)
+      cucumber-messages (~> 12.2, >= 12.2.0)
+      cucumber-wire (~> 3.1, >= 3.1.0)
+      diff-lcs (~> 1.3, >= 1.3, < 1.4)
+      multi_test (~> 0.1, >= 0.1.2)
+      sys-uname (~> 1.0, >= 1.0.2)
+    cucumber-core (7.1.0)
+      cucumber-gherkin (~> 14.0, >= 14.0.1)
+      cucumber-messages (~> 12.2, >= 12.2.0)
+      cucumber-tag-expressions (~> 2.0, >= 2.0.4)
+    cucumber-create-meta (1.0.0)
+      cucumber-messages (~> 12.2, >= 12.2.0)
+      sys-uname (~> 1.2, >= 1.2.1)
+    cucumber-cucumber-expressions (10.3.0)
+    cucumber-gherkin (14.2.0)
+      cucumber-messages (~> 12.4, >= 12.4.0)
+    cucumber-html-formatter (7.2.0)
+      cucumber-messages (~> 12.4, >= 12.4.0)
+    cucumber-messages (12.4.0)
+      protobuf-cucumber (~> 3.10, >= 3.10.8)
+    cucumber-rails (2.1.0)
+      capybara (>= 2.12, < 4)
+      cucumber (>= 3.0.2, < 5)
+      mime-types (>= 2.0, < 4)
+      nokogiri (~> 1.8)
+      rails (>= 4.2, < 7)
+    cucumber-tag-expressions (2.0.4)
+    cucumber-wire (3.1.0)
+      cucumber-core (~> 7.1, >= 7.1.0)
+      cucumber-cucumber-expressions (~> 10.1, >= 10.1.0)
+      cucumber-messages (~> 12.2, >= 12.2.0)
     dante (0.2.0)
-    database_cleaner (1.6.2)
+    database_cleaner (1.8.5)
     devise (4.7.1)
       bcrypt (~> 3.0)
       orm_adapter (~> 0.1)
@@ -121,10 +142,11 @@ GEM
       warden (~> 1.2.3)
     diff-lcs (1.3)
     docile (1.1.5)
-    dotenv (2.2.1)
-    dotenv-rails (2.2.1)
-      dotenv (= 2.2.1)
-      railties (>= 3.2, < 5.2)
+    dotenv (2.7.6)
+    dotenv-rails (2.7.6)
+      dotenv (= 2.7.6)
+      railties (>= 3.2)
+    erubi (1.9.0)
     erubis (2.7.0)
     execjs (2.7.0)
     factory_bot (4.8.2)
@@ -135,35 +157,39 @@ GEM
     faraday (0.14.0)
       multipart-post (>= 1.2, < 3)
     ffi (1.13.1)
-    gherkin (5.0.0)
     globalid (0.4.2)
       activesupport (>= 4.2.0)
-    i18n (0.9.5)
+    i18n (1.8.5)
       concurrent-ruby (~> 1.0)
     jquery-rails (4.4.0)
       rails-dom-testing (>= 1, < 3)
       railties (>= 4.2.0)
       thor (>= 0.14, < 2.0)
     json (2.3.1)
-    libv8 (8.4.255.0-x86_64-darwin-19)
-    loofah (2.4.0)
+    libv8 (8.4.255.0)
+    loofah (2.7.0)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     mail (2.7.1)
       mini_mime (>= 0.1.1)
-    mime-types (3.1)
+    marcel (0.3.3)
+      mimemagic (~> 0.3.2)
+    method_source (1.0.0)
+    middleware (0.1.0)
+    mime-types (3.3.1)
       mime-types-data (~> 3.2015)
-    mime-types-data (3.2016.0521)
-    mini_mime (1.0.1)
+    mime-types-data (3.2020.0512)
+    mimemagic (0.3.5)
+    mini_mime (1.0.2)
     mini_portile2 (2.4.0)
     mini_racer (0.3.1)
       libv8 (~> 8.4.255)
-    minitest (5.14.0)
+    minitest (5.14.2)
     multi_json (1.13.1)
     multi_test (0.1.2)
     multipart-post (2.0.0)
     nio4r (2.5.2)
-    nokogiri (1.10.9)
+    nokogiri (1.10.10)
       mini_portile2 (~> 2.4.0)
     orm_adapter (0.5.0)
     paper_trail (4.2.0)
@@ -176,30 +202,38 @@ GEM
       cliver (~> 0.3.1)
       websocket-driver (>= 0.2.0)
     popper_js (1.16.0)
+    protobuf-cucumber (3.10.8)
+      activesupport (>= 3.2)
+      middleware
+      thor
+      thread_safe
     public_suffix (3.0.2)
     puma (4.3.5)
       nio4r (~> 2.0)
-    rack (1.6.13)
-    rack-test (0.6.3)
-      rack (>= 1.0)
-    rails (4.2.11)
-      actionmailer (= 4.2.11)
-      actionpack (= 4.2.11)
-      actionview (= 4.2.11)
-      activejob (= 4.2.11)
-      activemodel (= 4.2.11)
-      activerecord (= 4.2.11)
-      activesupport (= 4.2.11)
-      bundler (>= 1.3.0, < 2.0)
-      railties (= 4.2.11)
-      sprockets-rails
+    rack (2.2.3)
+    rack-test (1.1.0)
+      rack (>= 1.0, < 3)
+    rails (5.2.4.3)
+      actioncable (= 5.2.4.3)
+      actionmailer (= 5.2.4.3)
+      actionpack (= 5.2.4.3)
+      actionview (= 5.2.4.3)
+      activejob (= 5.2.4.3)
+      activemodel (= 5.2.4.3)
+      activerecord (= 5.2.4.3)
+      activestorage (= 5.2.4.3)
+      activesupport (= 5.2.4.3)
+      bundler (>= 1.3.0)
+      railties (= 5.2.4.3)
+      sprockets-rails (>= 2.0.0)
     rails-assets-tether (1.1.1)
-    rails-deprecated_sanitizer (1.0.3)
-      activesupport (>= 4.2.0.alpha)
-    rails-dom-testing (1.0.9)
-      activesupport (>= 4.2.0, < 5.0)
-      nokogiri (~> 1.6)
-      rails-deprecated_sanitizer (>= 1.0.1)
+    rails-controller-testing (1.0.5)
+      actionpack (>= 5.0.1.rc1)
+      actionview (>= 5.0.1.rc1)
+      activesupport (>= 5.0.1.rc1)
+    rails-dom-testing (2.0.3)
+      activesupport (>= 4.2.0)
+      nokogiri (>= 1.6)
     rails-html-sanitizer (1.3.0)
       loofah (~> 2.3)
     rails_12factor (0.0.3)
@@ -215,11 +249,12 @@ GEM
       ruby-progressbar
     rails_serve_static_assets (0.0.5)
     rails_stdout_logging (0.0.5)
-    railties (4.2.11)
-      actionpack (= 4.2.11)
-      activesupport (= 4.2.11)
+    railties (5.2.4.3)
+      actionpack (= 5.2.4.3)
+      activesupport (= 5.2.4.3)
+      method_source
       rake (>= 0.8.7)
-      thor (>= 0.18.1, < 2.0)
+      thor (>= 0.19.0, < 2.0)
     rake (13.0.1)
     rb-fsevent (0.10.4)
     rb-inotify (0.10.1)
@@ -230,31 +265,31 @@ GEM
     responders (2.4.1)
       actionpack (>= 4.2.0, < 6.0)
       railties (>= 4.2.0, < 6.0)
-    rspec-core (3.7.1)
-      rspec-support (~> 3.7.0)
-    rspec-expectations (3.7.0)
+    rspec-core (3.9.2)
+      rspec-support (~> 3.9.3)
+    rspec-expectations (3.9.2)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.7.0)
-    rspec-mocks (3.7.0)
+      rspec-support (~> 3.9.0)
+    rspec-mocks (3.9.1)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.7.0)
-    rspec-rails (3.7.2)
-      actionpack (>= 3.0)
-      activesupport (>= 3.0)
-      railties (>= 3.0)
-      rspec-core (~> 3.7.0)
-      rspec-expectations (~> 3.7.0)
-      rspec-mocks (~> 3.7.0)
-      rspec-support (~> 3.7.0)
-    rspec-support (3.7.1)
+      rspec-support (~> 3.9.0)
+    rspec-rails (4.0.1)
+      actionpack (>= 4.2)
+      activesupport (>= 4.2)
+      railties (>= 4.2)
+      rspec-core (~> 3.9)
+      rspec-expectations (~> 3.9)
+      rspec-mocks (~> 3.9)
+      rspec-support (~> 3.9)
+    rspec-support (3.9.3)
     ruby-progressbar (1.9.0)
     sass (3.7.4)
       sass-listen (~> 4.0.0)
     sass-listen (4.0.0)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
-    sass-rails (5.0.7)
-      railties (>= 4.0.0, < 6)
+    sass-rails (5.1.0)
+      railties (>= 5.2.0)
       sass (~> 3.1)
       sprockets (>= 2.8, < 4.0)
       sprockets-rails (>= 2.0, < 4.0)
@@ -289,10 +324,12 @@ GEM
     stripe_event (2.3.1)
       activesupport (>= 3.1)
       stripe (>= 2.8, < 6)
+    sys-uname (1.2.1)
+      ffi (>= 1.0.0)
     thor (1.0.1)
     thread_safe (0.3.6)
     tilt (2.0.10)
-    tzinfo (1.2.6)
+    tzinfo (1.2.7)
       thread_safe (~> 0.1)
     uglifier (2.7.2)
       execjs (>= 0.3.0)
@@ -312,17 +349,18 @@ PLATFORMS
 DEPENDENCIES
   brakeman (~> 3.3)
   codeclimate-test-reporter
-  cucumber-rails (~> 1.4.4)
+  cucumber-rails (~> 2.1)
   database_cleaner
-  devise (>= 4.6.0)
-  dotenv-rails
+  devise (~> 4.7)
+  dotenv-rails (~> 2.7)
   factory_bot_rails
   pg (= 0.20)
   poltergeist
   puma
+  rails-controller-testing
   rails_12factor
   rails_best_practices (~> 1.17)
-  rspec-rails
+  rspec-rails (~> 4.0.1)
   stripe-ruby-mock (~> 2.5.2)
   tang!
 
diff --git a/app/models/tang/coupon.rb b/app/models/tang/coupon.rb
index ae5cb0a..c316a26 100644
--- a/app/models/tang/coupon.rb
+++ b/app/models/tang/coupon.rb
@@ -11,12 +11,12 @@ class Coupon < ActiveRecord::Base
     validates :stripe_id, uniqueness: true # , if: "deleted_at.nil?"
     validates :duration, inclusion: { in: %w(once repeating forever) }
     validates :amount_off, numericality: { only_integer: true, greater_than: 0 }, allow_nil: true
-    validates :currency, presence: true, if: "amount_off.present?"
+    validates :currency, presence: true, if: -> { amount_off.present? }
     validates :duration_in_months, presence: true, numericality: { only_integer: true, greater_than: 0 }, if: :repeating?
     validates :max_redemptions, numericality: { only_integer: true, greater_than: 0 }, allow_nil: true
     validates :percent_off, numericality: { only_integer: true, greater_than_or_equal_to: 1, less_than_or_equal_to: 100 },
-                            presence: true, if: "amount_off.nil?"
-    validates :redeem_by, future: true, if: "redeem_by.present?"
+                            presence: true, if: -> { amount_off.nil? }
+    validates :redeem_by, future: true, if: -> { redeem_by.present? }
 
     before_create :create_stripe_coupon
     before_update :update_stripe_coupon
diff --git a/app/models/tang/plan.rb b/app/models/tang/plan.rb
index f183c68..32cf47d 100644
--- a/app/models/tang/plan.rb
+++ b/app/models/tang/plan.rb
@@ -11,10 +11,10 @@ class Plan < ActiveRecord::Base
     validates :amount, numericality: { only_integer: true, greater_than_or_equal_to: 0 }
     validates :currency, length: { is: 3 }
     validates :interval, inclusion: { in: %w(day week month year) }
-    validates :interval_count, numericality: { only_integer: true, greater_than: 0, less_than_or_equal_to: 1 }, allow_nil: true, if: "interval == 'year'"
-    validates :interval_count, numericality: { only_integer: true, greater_than: 0, less_than_or_equal_to: 12 }, allow_nil: true, if: "interval == 'month'"
-    validates :interval_count, numericality: { only_integer: true, greater_than: 0, less_than_or_equal_to: 52 }, allow_nil: true, if: "interval == 'week'"
-    validates :interval_count, numericality: { only_integer: true, greater_than: 0, less_than_or_equal_to: 365 }, allow_nil: true, if: "interval == 'day'"
+    validates :interval_count, numericality: { only_integer: true, greater_than: 0, less_than_or_equal_to: 1 }, allow_nil: true, if: -> { interval == 'year' }
+    validates :interval_count, numericality: { only_integer: true, greater_than: 0, less_than_or_equal_to: 12 }, allow_nil: true, if: -> { interval == 'month' }
+    validates :interval_count, numericality: { only_integer: true, greater_than: 0, less_than_or_equal_to: 52 }, allow_nil: true, if: -> { interval == 'week' }
+    validates :interval_count, numericality: { only_integer: true, greater_than: 0, less_than_or_equal_to: 365 }, allow_nil: true, if: -> { interval == 'day' }
     validates :trial_period_days, numericality: { only_integer: true, greater_than: 0 }, allow_nil: true
     validates :statement_descriptor, length: { maximum: 22 }, format: { without: /[<>"']/ }, allow_nil: true
 
diff --git a/bin/rails b/bin/rails
index a0a4415..64b5a04 100755
--- a/bin/rails
+++ b/bin/rails
@@ -1,11 +1,13 @@
 #!/usr/bin/env ruby
-# This command will automatically be run when you run "rails" with Rails 4 gems installed from the root of your application.
+# This command will automatically be run when you run "rails" with Rails gems
+# installed from the root of your application.
 
-ENGINE_ROOT = File.expand_path('../..', __FILE__)
-ENGINE_PATH = File.expand_path('../../lib/tang/engine', __FILE__)
+ENGINE_ROOT = File.expand_path('..', __dir__)
+ENGINE_PATH = File.expand_path('../lib/tang/engine', __dir__)
+APP_PATH = File.expand_path('../test/dummy/config/application', __dir__)
 
 # Set up gems listed in the Gemfile.
-ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../Gemfile', __FILE__)
+ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
 require 'bundler/setup' if File.exist?(ENV['BUNDLE_GEMFILE'])
 
 require 'rails/all'
diff --git a/config/cucumber.yml b/config/cucumber.yml
index 19b288d..74fb114 100644
--- a/config/cucumber.yml
+++ b/config/cucumber.yml
@@ -1,8 +1,8 @@
 <%
 rerun = File.file?('rerun.txt') ? IO.read('rerun.txt') : ""
 rerun_opts = rerun.to_s.strip.empty? ? "--format #{ENV['CUCUMBER_FORMAT'] || 'progress'} features" : "--format #{ENV['CUCUMBER_FORMAT'] || 'pretty'} #{rerun}"
-std_opts = "--format #{ENV['CUCUMBER_FORMAT'] || 'pretty'} --strict --tags ~@wip"
+std_opts = "--format #{ENV['CUCUMBER_FORMAT'] || 'pretty'} --strict --tags not @wip"
 %>
 default: <%= std_opts %> features
 wip: --tags @wip:3 --wip features
-rerun: <%= rerun_opts %> --format rerun --out rerun.txt --strict --tags ~@wip
+rerun: <%= rerun_opts %> --format rerun --out rerun.txt --strict --tags not @wip
diff --git a/features/support/env.rb b/features/support/env.rb
index 6e01fd4..656aa8c 100644
--- a/features/support/env.rb
+++ b/features/support/env.rb
@@ -42,7 +42,7 @@
 # Remove/comment out the lines below if your app doesn't have a database.
 # For some databases (like MongoDB and CouchDB) you may need to use :truncation instead.
 begin
-  DatabaseCleaner.strategy = :transaction
+  DatabaseCleaner.strategy = :transaction #, except: %w(ar_internal_metadata)
 rescue NameError
   raise "You need to add database_cleaner to your Gemfile (in the :test group) if you wish to use it."
 end
diff --git a/lib/tang/version.rb b/lib/tang/version.rb
index c032f44..53568fd 100644
--- a/lib/tang/version.rb
+++ b/lib/tang/version.rb
@@ -1,3 +1,3 @@
 module Tang
-  VERSION = "0.0.7"
+  VERSION = "0.0.8"
 end
diff --git a/spec/controllers/tang/admin/customers_controller_spec.rb b/spec/controllers/tang/admin/customers_controller_spec.rb
index 8d86858..9f8a917 100644
--- a/spec/controllers/tang/admin/customers_controller_spec.rb
+++ b/spec/controllers/tang/admin/customers_controller_spec.rb
@@ -55,7 +55,7 @@ module Tang
     describe "GET #show" do
       it "assigns the requested customer as @customer" do
         customer = User.create! valid_attributes
-        get :show, {id: customer.to_param}, session: valid_session
+        get :show, params: {id: customer.to_param}, session: valid_session
         expect(assigns(:customer)).to eq(customer)
       end
     end
@@ -63,7 +63,7 @@ module Tang
     describe "GET #edit" do
       it "assigns the requested customer as @customer" do
         customer = User.create! valid_attributes
-        get :edit, {id: customer.to_param}, session: valid_session
+        get :edit, params: {id: customer.to_param}, session: valid_session
         expect(assigns(:customer)).to eq(customer)
       end
     end
@@ -77,7 +77,7 @@ module Tang
 
         it "updates the requested customer" do
           customer = User.create! valid_attributes
-          put :update, {id: customer.to_param, user: new_attributes}, session: valid_session
+          put :update, params: {id: customer.to_param, user: new_attributes}, session: valid_session
           customer.reload
           # skip("Add assertions for updated state")
           expect(customer.email).to eq('new@email.com')
@@ -85,13 +85,13 @@ module Tang
 
         it "assigns the requested customer as @customer" do
           customer = User.create! valid_attributes
-          put :update, {id: customer.to_param, user: valid_attributes}, session: valid_session
+          put :update, params: {id: customer.to_param, user: valid_attributes}, session: valid_session
           expect(assigns(:customer)).to eq(customer)
         end
 
         it "redirects to the customer" do
           customer = User.create! valid_attributes
-          put :update, {id: customer.to_param, user: valid_attributes}, session: valid_session
+          put :update, params: {id: customer.to_param, user: valid_attributes}, session: valid_session
           expect(response).to redirect_to(admin_customer_url(customer))
         end
       end
@@ -99,13 +99,13 @@ module Tang
       context "with invalid params" do
         it "assigns the customer as @customer" do
           customer = User.create! valid_attributes
-          put :update, {id: customer.to_param, user: invalid_attributes}, session: valid_session
+          put :update, params: {id: customer.to_param, user: invalid_attributes}, session: valid_session
           expect(assigns(:customer)).to eq(customer)
         end
 
         it "re-renders the 'edit' template" do
           customer = User.create! valid_attributes
-          put :update, {id: customer.to_param, user: invalid_attributes}, session: valid_session
+          put :update, params: {id: customer.to_param, user: invalid_attributes}, session: valid_session
           expect(response).to render_template("edit")
         end
       end
@@ -115,13 +115,13 @@ module Tang
       it "destroys the requested customer" do
         customer = User.create! valid_attributes
         expect {
-          delete :destroy, {id: customer.to_param}, session: valid_session
+          delete :destroy, params: {id: customer.to_param}, session: valid_session
         }.to change(User, :count).by(-1)
       end
 
       it "redirects to the customers list" do
         customer = User.create! valid_attributes
-        delete :destroy, {id: customer.to_param}, session: valid_session
+        delete :destroy, params: {id: customer.to_param}, session: valid_session
         expect(response).to redirect_to(admin_customers_url)
       end
     end
diff --git a/spec/controllers/tang/admin/plans_controller_spec.rb b/spec/controllers/tang/admin/plans_controller_spec.rb
index 02130e3..796e452 100644
--- a/spec/controllers/tang/admin/plans_controller_spec.rb
+++ b/spec/controllers/tang/admin/plans_controller_spec.rb
@@ -55,7 +55,7 @@ module Tang
     describe "GET #show" do
       it "assigns the requested plan as @plan" do
         plan = Plan.create! valid_attributes
-        get :show, {id: plan.to_param}, session: valid_session
+        get :show, params: {id: plan.to_param}, session: valid_session
         expect(assigns(:plan)).to eq(plan)
       end
     end
@@ -70,7 +70,7 @@ module Tang
     describe "GET #edit" do
       it "assigns the requested plan as @plan" do
         plan = Plan.create! valid_attributes
-        get :edit, {id: plan.to_param}, session: valid_session
+        get :edit, params: {id: plan.to_param}, session: valid_session
         expect(assigns(:plan)).to eq(plan)
       end
     end
@@ -79,30 +79,30 @@ module Tang
       context "with valid params" do
         it "creates a new Plan" do
           expect {
-            post :create, {plan: valid_attributes}, session: valid_session
+            post :create, params: {plan: valid_attributes}, session: valid_session
           }.to change(Plan, :count).by(1)
         end
 
         it "assigns a newly created plan as @plan" do
-          post :create, {plan: valid_attributes}, session: valid_session
+          post :create, params: {plan: valid_attributes}, session: valid_session
           expect(assigns(:plan)).to be_a(Plan)
           expect(assigns(:plan)).to be_persisted
         end
 
         it "redirects to the created plan" do
-          post :create, {plan: valid_attributes}, session: valid_session
+          post :create, params: {plan: valid_attributes}, session: valid_session
           expect(response).to redirect_to(admin_plan_url(Plan.last))
         end
       end
 
       context "with invalid params" do
         it "assigns a newly created but unsaved plan as @plan" do
-          post :create, {plan: invalid_attributes}, session: valid_session
+          post :create, params: {plan: invalid_attributes}, session: valid_session
           expect(assigns(:plan)).to be_a_new(Plan)
         end
 
         it "re-renders the 'new' template" do
-          post :create, {plan: invalid_attributes}, session: valid_session
+          post :create, params: {plan: invalid_attributes}, session: valid_session
           expect(response).to render_template("new")
         end
       end
@@ -117,7 +117,7 @@ module Tang
 
         it "updates the requested plan" do
           plan = Plan.create! valid_attributes
-          put :update, {id: plan.to_param, plan: new_attributes}, session: valid_session
+          put :update, params: {id: plan.to_param, plan: new_attributes}, session: valid_session
           plan.reload
           # skip("Add assertions for updated state")
           expect(plan.name).to eq('Changed Plan')
@@ -125,13 +125,13 @@ module Tang
 
         it "assigns the requested plan as @plan" do
           plan = Plan.create! valid_attributes
-          put :update, {id: plan.to_param, plan: valid_attributes}, session: valid_session
+          put :update, params: {id: plan.to_param, plan: valid_attributes}, session: valid_session
           expect(assigns(:plan)).to eq(plan)
         end
 
         it "redirects to the plan" do
           plan = Plan.create! valid_attributes
-          put :update, {id: plan.to_param, plan: valid_attributes}, session: valid_session
+          put :update, params: {id: plan.to_param, plan: valid_attributes}, session: valid_session
           expect(response).to redirect_to(admin_plan_url(plan))
         end
       end
@@ -139,13 +139,13 @@ module Tang
       context "with invalid params" do
         it "assigns the plan as @plan" do
           plan = Plan.create! valid_attributes
-          put :update, {id: plan.to_param, plan: invalid_attributes}, session: valid_session
+          put :update, params: {id: plan.to_param, plan: invalid_attributes}, session: valid_session
           expect(assigns(:plan)).to eq(plan)
         end
 
         it "re-renders the 'edit' template" do
           plan = Plan.create! valid_attributes
-          put :update, {id: plan.to_param, plan: invalid_attributes}, session: valid_session
+          put :update, params: {id: plan.to_param, plan: invalid_attributes}, session: valid_session
           expect(response).to render_template("edit")
         end
       end
@@ -155,13 +155,13 @@ module Tang
       it "destroys the requested plan" do
         plan = Plan.create! valid_attributes
         expect {
-          delete :destroy, {id: plan.to_param}, session: valid_session
+          delete :destroy, params: {id: plan.to_param}, session: valid_session
         }.to change(Plan, :count).by(-1)
       end
 
       it "redirects to the plans list" do
         plan = Plan.create! valid_attributes
-        delete :destroy, {id: plan.to_param}, session: valid_session
+        delete :destroy, params: {id: plan.to_param}, session: valid_session
         expect(response).to redirect_to(admin_plans_url)
       end
     end
diff --git a/spec/controllers/tang/admin/subscriptions_controller_spec.rb b/spec/controllers/tang/admin/subscriptions_controller_spec.rb
index 839171d..c2395a7 100644
--- a/spec/controllers/tang/admin/subscriptions_controller_spec.rb
+++ b/spec/controllers/tang/admin/subscriptions_controller_spec.rb
@@ -57,7 +57,7 @@ module Tang
       it "assigns the requested subscription as @subscription" do
         # subscription = Subscription.create! valid_attributes
         subscription = FactoryBot.create(:subscription)
-        get :show, {id: subscription.to_param}, session: valid_session
+        get :show, params: {id: subscription.to_param}, session: valid_session
         expect(assigns(:subscription)).to eq(subscription)
       end
     end
@@ -66,7 +66,7 @@ module Tang
       it "assigns the requested subscription as @subscription" do
         # subscription = Subscription.create! valid_attributes
         subscription = FactoryBot.create(:subscription)
-        get :edit, {id: subscription.to_param}, session: valid_session
+        get :edit, params: {id: subscription.to_param}, session: valid_session
         expect(assigns(:subscription)).to eq(subscription)
       end
     end
@@ -81,7 +81,7 @@ module Tang
         it "updates the requested subscription" do
           # subscription = Subscription.create! valid_attributes
           subscription = FactoryBot.create(:subscription)
-          put :update, {id: subscription.to_param, subscription: new_attributes}, session: valid_session
+          put :update, params: {id: subscription.to_param, subscription: new_attributes}, session: valid_session
           subscription.reload
           # skip("Add assertions for updated state")
           expect(subscription.quantity).to eq(2)
@@ -90,14 +90,14 @@ module Tang
         it "assigns the requested subscription as @subscription" do
           # subscription = Subscription.create! valid_attributes
           subscription = FactoryBot.create(:subscription)
-          put :update, {id: subscription.to_param, subscription: valid_attributes}, session: valid_session
+          put :update, params: {id: subscription.to_param, subscription: valid_attributes}, session: valid_session
           expect(assigns(:subscription)).to eq(subscription)
         end
 
         it "redirects to the subscription" do
           # subscription = Subscription.create! valid_attributes
           subscription = FactoryBot.create(:subscription)
-          put :update, {id: subscription.to_param, subscription: valid_attributes}, session: valid_session
+          put :update, params: {id: subscription.to_param, subscription: valid_attributes}, session: valid_session
           expect(response).to redirect_to(admin_subscription_url(subscription))
         end
       end
@@ -106,14 +106,14 @@ module Tang
         it "assigns the subscription as @subscription" do
           # subscription = Subscription.create! valid_attributes
           subscription = FactoryBot.create(:subscription)
-          put :update, {id: subscription.to_param, subscription: invalid_attributes}, session: valid_session
+          put :update, params: {id: subscription.to_param, subscription: invalid_attributes}, session: valid_session
           expect(assigns(:subscription)).to eq(subscription)
         end
 
         it "re-renders the 'edit' template" do
           # subscription = Subscription.create! valid_attributes
           subscription = FactoryBot.create(:subscription)
-          put :update, {id: subscription.to_param, subscription: invalid_attributes}, session: valid_session
+          put :update, params: {id: subscription.to_param, subscription: invalid_attributes}, session: valid_session
           expect(response).to render_template("edit")
         end
       end
@@ -124,14 +124,14 @@ module Tang
         # subscription = Subscription.create! valid_attributes
         subscription = FactoryBot.create(:subscription)
         expect {
-          delete :destroy, {id: subscription.to_param}, session: valid_session
+          delete :destroy, params: {id: subscription.to_param}, session: valid_session
         }.to change(Subscription.where.not(status: :canceled), :count).by(-1)
       end
 
       it "redirects to the subscriptions list" do
         # subscription = Subscription.create! valid_attributes
         subscription = FactoryBot.create(:subscription)
-        delete :destroy, {id: subscription.to_param}, session: valid_session
+        delete :destroy, params: {id: subscription.to_param}, session: valid_session
         expect(response).to redirect_to(admin_subscriptions_url)
       end
     end
diff --git a/spec/requests/stripe_event_spec.rb b/spec/requests/stripe_event_spec.rb
index e78ca9a..0058757 100644
--- a/spec/requests/stripe_event_spec.rb
+++ b/spec/requests/stripe_event_spec.rb
@@ -20,7 +20,7 @@ def bypass_event_signature(payload)
 
       deliveries = Tang::StripeMailer.deliveries.length
 
-      post '/stripe_event', id: event.id
+      post '/stripe_event', params: { id: event.id }
       expect(response.code).to eq('200')
 
       expect(Tang::StripeMailer.deliveries.length).to eq(deliveries + 1)
@@ -36,7 +36,7 @@ def bypass_event_signature(payload)
       dispute_object = event.data.object
       bypass_event_signature(event.to_json)
 
-      post '/stripe_event', id: event.id
+      post '/stripe_event', params: { id: event.id }
       expect(response.code).to eq('200')
 
       expect(dispute_object.id).to_not be_nil
@@ -50,7 +50,7 @@ def bypass_event_signature(payload)
       dispute_object = event.data.object
       bypass_event_signature(event.to_json)
 
-      post '/stripe_event', id: event.id
+      post '/stripe_event', params: { id: event.id }
       expect(response.code).to eq('200')
 
       expect(dispute_object.id).to_not be_nil
@@ -64,7 +64,7 @@ def bypass_event_signature(payload)
       invoice_object = event.data.object
       bypass_event_signature(event.to_json)
 
-      post '/stripe_event', id: event.id
+      post '/stripe_event', params: { id: event.id }
       expect(response.code).to eq('200')
 
       expect(invoice_object.id).to_not be_nil
@@ -98,7 +98,7 @@ def bypass_event_signature(payload)
 
       deliveries = Tang::StripeMailer.deliveries.length
 
-      post '/stripe_event', id: event.id
+      post '/stripe_event', params: { id: event.id }
       expect(response.code).to eq('200')
 
       expect(Tang::StripeMailer.deliveries.length).to eq(deliveries + 2)
@@ -136,7 +136,7 @@ def bypass_event_signature(payload)
 
       deliveries = Tang::StripeMailer.deliveries.length
 
-      post '/stripe_event', id: event.id
+      post '/stripe_event', params: { id: event.id }
       expect(response.code).to eq('200')
 
       expect(Tang::StripeMailer.deliveries.length).to eq(deliveries + 2)
@@ -155,7 +155,7 @@ def bypass_event_signature(payload)
       subscription_object = event.data.object
       bypass_event_signature(event.to_json)
 
-      post '/stripe_event', id: event.id
+      post '/stripe_event', params: { id: event.id }
       expect(response.code).to eq('200')
 
       expect(subscription_object.id).to_not be_nil
diff --git a/spec/tang_app/config/application.rb b/spec/tang_app/config/application.rb
index ec4fdd6..7c2c59f 100644
--- a/spec/tang_app/config/application.rb
+++ b/spec/tang_app/config/application.rb
@@ -30,7 +30,7 @@ class Application < Rails::Application
     # config.i18n.default_locale = :de
 
     # Do not swallow errors in after_commit/after_rollback callbacks.
-    config.active_record.raise_in_transactional_callbacks = true
+    # config.active_record.raise_in_transactional_callbacks = true
 
     config.action_mailer.preview_path = File.expand_path('../../../../spec/mailers/previews', __FILE__)
   end
diff --git a/spec/tang_app/config/environments/production.rb b/spec/tang_app/config/environments/production.rb
index 641aacb..7a8696a 100644
--- a/spec/tang_app/config/environments/production.rb
+++ b/spec/tang_app/config/environments/production.rb
@@ -67,7 +67,7 @@
 
   # Enable locale fallbacks for I18n (makes lookups for any locale fall back to
   # the I18n.default_locale when a translation cannot be found).
-  config.i18n.fallbacks = true
+  config.i18n.fallbacks = [I18n.default_locale]
 
   # Send deprecation notices to registered listeners.
   config.active_support.deprecation = :notify
diff --git a/tang.gemspec b/tang.gemspec
index 8d8623c..fe22c21 100644
--- a/tang.gemspec
+++ b/tang.gemspec
@@ -18,7 +18,7 @@ Gem::Specification.new do |s|
 
   s.test_files = Dir["spec/**/*"]
   
-  s.add_dependency "rails", "~> 4.2"
+  s.add_dependency "rails", "~> 5.2"
   s.add_dependency 'stripe', '~> 3.9'
   s.add_dependency 'stripe_event', '~> 2.1'
   s.add_dependency 'paper_trail', '~> 4.2'