diff --git a/composer.json b/composer.json
index 44318d4..5b52212 100644
--- a/composer.json
+++ b/composer.json
@@ -28,7 +28,7 @@
     },
 
     "require-dev": {
-        "symfony/var-dumper": "^3.2",
+        "symfony/var-dumper": "^4.2",
         "phpunit/phpunit": "^6.1"
     }
 }
diff --git a/composer.lock b/composer.lock
index c582e70..9b3e120 100644
--- a/composer.lock
+++ b/composer.lock
@@ -1,10 +1,10 @@
 {
     "_readme": [
         "This file locks the dependencies of your project to a known state",
-        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
+        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "3a6a15906ab9957b8b500f671176e280",
+    "content-hash": "e70929cc1a3ee4b9bb8f8a7fad6784ce",
     "packages": [
         {
             "name": "kassner/log-parser",
@@ -1630,16 +1630,16 @@
         },
         {
             "name": "symfony/polyfill-mbstring",
-            "version": "v1.3.0",
+            "version": "v1.10.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/polyfill-mbstring.git",
-                "reference": "e79d363049d1c2128f133a2667e4f4190904f7f4"
+                "reference": "c79c051f5b3a46be09205c73b80b346e4153e494"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/polyfill-mbstring/zipball/e79d363049d1c2128f133a2667e4f4190904f7f4",
-                "reference": "e79d363049d1c2128f133a2667e4f4190904f7f4",
+                "url": "https://api.github.com/repos/symfony/polyfill-mbstring/zipball/c79c051f5b3a46be09205c73b80b346e4153e494",
+                "reference": "c79c051f5b3a46be09205c73b80b346e4153e494",
                 "shasum": ""
             },
             "require": {
@@ -1651,7 +1651,7 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "1.3-dev"
+                    "dev-master": "1.9-dev"
                 }
             },
             "autoload": {
@@ -1685,41 +1685,104 @@
                 "portable",
                 "shim"
             ],
-            "time": "2016-11-14T01:06:16+00:00"
+            "time": "2018-09-21T13:07:52+00:00"
+        },
+        {
+            "name": "symfony/polyfill-php72",
+            "version": "v1.10.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/symfony/polyfill-php72.git",
+                "reference": "9050816e2ca34a8e916c3a0ae8b9c2fccf68b631"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/symfony/polyfill-php72/zipball/9050816e2ca34a8e916c3a0ae8b9c2fccf68b631",
+                "reference": "9050816e2ca34a8e916c3a0ae8b9c2fccf68b631",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=5.3.3"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "1.9-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "Symfony\\Polyfill\\Php72\\": ""
+                },
+                "files": [
+                    "bootstrap.php"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Nicolas Grekas",
+                    "email": "p@tchwork.com"
+                },
+                {
+                    "name": "Symfony Community",
+                    "homepage": "https://symfony.com/contributors"
+                }
+            ],
+            "description": "Symfony polyfill backporting some PHP 7.2+ features to lower PHP versions",
+            "homepage": "https://symfony.com",
+            "keywords": [
+                "compatibility",
+                "polyfill",
+                "portable",
+                "shim"
+            ],
+            "time": "2018-09-21T13:07:52+00:00"
         },
         {
             "name": "symfony/var-dumper",
-            "version": "v3.2.8",
+            "version": "v4.2.2",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/var-dumper.git",
-                "reference": "fa47963ac7979ddbd42b2d646d1b056bddbf7bb8"
+                "reference": "85bde661b178173d85c6f11ea9d03b61d1212bb2"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/var-dumper/zipball/fa47963ac7979ddbd42b2d646d1b056bddbf7bb8",
-                "reference": "fa47963ac7979ddbd42b2d646d1b056bddbf7bb8",
+                "url": "https://api.github.com/repos/symfony/var-dumper/zipball/85bde661b178173d85c6f11ea9d03b61d1212bb2",
+                "reference": "85bde661b178173d85c6f11ea9d03b61d1212bb2",
                 "shasum": ""
             },
             "require": {
-                "php": ">=5.5.9",
-                "symfony/polyfill-mbstring": "~1.0"
+                "php": "^7.1.3",
+                "symfony/polyfill-mbstring": "~1.0",
+                "symfony/polyfill-php72": "~1.5"
             },
             "conflict": {
-                "phpunit/phpunit": "<4.8.35|<5.4.3,>=5.0"
+                "phpunit/phpunit": "<4.8.35|<5.4.3,>=5.0",
+                "symfony/console": "<3.4"
             },
             "require-dev": {
                 "ext-iconv": "*",
-                "twig/twig": "~1.20|~2.0"
+                "symfony/console": "~3.4|~4.0",
+                "symfony/process": "~3.4|~4.0",
+                "twig/twig": "~1.34|~2.4"
             },
             "suggest": {
                 "ext-iconv": "To convert non-UTF-8 strings to UTF-8 (or symfony/polyfill-iconv in case ext-iconv cannot be used).",
-                "ext-symfony_debug": ""
+                "ext-intl": "To show region name in time zone dump",
+                "symfony/console": "To use the ServerDumpCommand and/or the bin/var-dump-server script"
             },
+            "bin": [
+                "Resources/bin/var-dump-server"
+            ],
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "3.2-dev"
+                    "dev-master": "4.2-dev"
                 }
             },
             "autoload": {
@@ -1753,7 +1816,7 @@
                 "debug",
                 "dump"
             ],
-            "time": "2017-05-01T14:55:58+00:00"
+            "time": "2019-01-03T09:07:35+00:00"
         },
         {
             "name": "theseer/tokenizer",