release: 1.4.0 readiness

- Updates branch aliases:
  - dev-master => 1.4.x-dev
  - dev-develop => 1.5.x-dev
- Prepares CHANGELOG:
  - Removes empty 1.3.2 release stub.
  - Sets date for 1.4.0 release.

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 All notable changes to this project will be documented in this file, in reverse chronological order by release.
 
-## 1.4.0 - TBD
+## 1.4.0 - 2019-03-13
 
 ### Added
 
@@ -25,28 +25,6 @@ All notable changes to this project will be documented in this file, in reverse
 
 - Nothing.
 
-## 1.3.2 - TBD
-
-### Added
-
-- Nothing.
-
-### Changed
-
-- Nothing.
-
-### Deprecated
-
-- Nothing.
-
-### Removed
-
-- Nothing.
-
-### Fixed
-
-- Nothing.
-
 ## 1.3.1 - 2019-02-07
 
 ### Added

composer.json

@@ -40,8 +40,8 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-master": "1.3.x-dev",
-            "dev-develop": "1.4.x-dev"
+            "dev-master": "1.4.x-dev",
+            "dev-develop": "1.5.x-dev"
         }
     }
 }