Fix dependencies.

composer.lock

@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
         "This file is @generated automatically"
     ],
-    "content-hash": "723debc6d424bd1cd8c84d1d42f014c6",
+    "content-hash": "98d5bc8ff0e066bda4383130af3ae190",
     "packages": [
         {
             "name": "composer/installers",
@@ -562,32 +562,32 @@
         },
         {
             "name": "symfony/debug",
-            "version": "v4.0.1",
+            "version": "v3.4.1",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/debug.git",
-                "reference": "26a15dab86c3820473716be4f846eac774ad4ad9"
+                "reference": "fb2001e5d85f95d8b6ab94ae3be5d2672df128fd"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/debug/zipball/26a15dab86c3820473716be4f846eac774ad4ad9",
-                "reference": "26a15dab86c3820473716be4f846eac774ad4ad9",
+                "url": "https://api.github.com/repos/symfony/debug/zipball/fb2001e5d85f95d8b6ab94ae3be5d2672df128fd",
+                "reference": "fb2001e5d85f95d8b6ab94ae3be5d2672df128fd",
                 "shasum": ""
             },
             "require": {
-                "php": "^7.1.3",
+                "php": "^5.5.9|>=7.0.8",
                 "psr/log": "~1.0"
             },
             "conflict": {
-                "symfony/http-kernel": "<3.4"
+                "symfony/http-kernel": ">=2.3,<2.3.24|~2.4.0|>=2.5,<2.5.9|>=2.6,<2.6.2"
             },
             "require-dev": {
-                "symfony/http-kernel": "~3.4|~4.0"
+                "symfony/http-kernel": "~2.8|~3.0|~4.0"
             },
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "4.0-dev"
+                    "dev-master": "3.4-dev"
                 }
             },
             "autoload": {
@@ -614,7 +614,7 @@
             ],
             "description": "Symfony Debug Component",
             "homepage": "https://symfony.com",
-            "time": "2017-11-21T09:27:49+00:00"
+            "time": "2017-11-21T09:01:46+00:00"
         },
         {
             "name": "symfony/polyfill-mbstring",