diff --git a/composer.lock b/composer.lock
index ab7581ea6af395562976200c18d1f990da6ffe06..b4af03638c07c58effb366ad1de62f89e3b85f8a 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,8 @@
         "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": "2a8d72f5e37a334e64369e5643771125",
+    "hash": "a1ec673cce9acc0b51f539956596145e",
+    "content-hash": "ea73e02f0531f0013dd750a39647e36b",
     "packages": [
         {
             "name": "gettext/gettext",
@@ -64,7 +65,7 @@
                 "po",
                 "translation"
             ],
-            "time": "2016-08-01T18:09:57+00:00"
+            "time": "2016-08-01 18:09:57"
         },
         {
             "name": "gettext/languages",
@@ -125,7 +126,7 @@
                 "translations",
                 "unicode"
             ],
-            "time": "2017-03-23T17:02:28+00:00"
+            "time": "2017-03-23 17:02:28"
         },
         {
             "name": "jaimeperez/twig-configurable-i18n",
@@ -169,7 +170,7 @@
                 "translation",
                 "twig"
             ],
-            "time": "2016-10-03T12:34:15+00:00"
+            "time": "2016-10-03 12:34:15"
         },
         {
             "name": "psr/log",
@@ -216,7 +217,7 @@
                 "psr",
                 "psr-3"
             ],
-            "time": "2016-10-10T12:19:37+00:00"
+            "time": "2016-10-10 12:19:37"
         },
         {
             "name": "robrichards/xmlseclibs",
@@ -257,7 +258,7 @@
                 "xml",
                 "xmldsig"
             ],
-            "time": "2016-09-08T13:15:00+00:00"
+            "time": "2016-09-08 13:15:00"
         },
         {
             "name": "simplesamlphp/saml2",
@@ -362,7 +363,7 @@
                 "i18n",
                 "text"
             ],
-            "time": "2016-10-25T17:34:14+00:00"
+            "time": "2016-10-25 17:34:14"
         },
         {
             "name": "twig/twig",
@@ -424,7 +425,7 @@
             "keywords": [
                 "templating"
             ],
-            "time": "2017-04-20T17:39:48+00:00"
+            "time": "2017-04-20 17:39:48"
         },
         {
             "name": "whitehat101/apr1-md5",
@@ -468,7 +469,7 @@
                 "MD5",
                 "apr1"
             ],
-            "time": "2015-02-11T11:06:42+00:00"
+            "time": "2015-02-11 11:06:42"
         }
     ],
     "packages-dev": [
@@ -524,7 +525,7 @@
                 "constructor",
                 "instantiate"
             ],
-            "time": "2015-06-14T21:17:01+00:00"
+            "time": "2015-06-14 21:17:01"
         },
         {
             "name": "guzzle/guzzle",
@@ -620,7 +621,53 @@
                 "web service"
             ],
             "abandoned": "guzzlehttp/guzzle",
-            "time": "2015-03-18T18:23:50+00:00"
+            "time": "2015-03-18 18:23:50"
+        },
+        {
+            "name": "mikey179/vfsStream",
+            "version": "v1.6.4",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/mikey179/vfsStream.git",
+                "reference": "0247f57b2245e8ad2e689d7cee754b45fbabd592"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/mikey179/vfsStream/zipball/0247f57b2245e8ad2e689d7cee754b45fbabd592",
+                "reference": "0247f57b2245e8ad2e689d7cee754b45fbabd592",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=5.3.0"
+            },
+            "require-dev": {
+                "phpunit/phpunit": "~4.5"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "1.6.x-dev"
+                }
+            },
+            "autoload": {
+                "psr-0": {
+                    "org\\bovigo\\vfs\\": "src/main/php"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "BSD-3-Clause"
+            ],
+            "authors": [
+                {
+                    "name": "Frank Kleine",
+                    "homepage": "http://frankkleine.de/",
+                    "role": "Developer"
+                }
+            ],
+            "description": "Virtual file system to mock the real file system in unit tests.",
+            "homepage": "http://vfs.bovigo.org/",
+            "time": "2016-07-18 14:02:57"
         },
         {
             "name": "phpdocumentor/reflection-common",
@@ -674,7 +721,7 @@
                 "reflection",
                 "static analysis"
             ],
-            "time": "2015-12-27T11:43:31+00:00"
+            "time": "2015-12-27 11:43:31"
         },
         {
             "name": "phpdocumentor/reflection-docblock",
@@ -719,7 +766,7 @@
                 }
             ],
             "description": "With this component, a library can provide support for annotations via DocBlocks or otherwise retrieve information that is embedded in a DocBlock.",
-            "time": "2016-09-30T07:12:33+00:00"
+            "time": "2016-09-30 07:12:33"
         },
         {
             "name": "phpdocumentor/type-resolver",
@@ -766,7 +813,7 @@
                     "email": "me@mikevanriel.com"
                 }
             ],
-            "time": "2016-11-25T06:54:22+00:00"
+            "time": "2016-11-25 06:54:22"
         },
         {
             "name": "phpspec/prophecy",
@@ -829,7 +876,7 @@
                 "spy",
                 "stub"
             ],
-            "time": "2017-03-02T20:05:34+00:00"
+            "time": "2017-03-02 20:05:34"
         },
         {
             "name": "phpunit/php-code-coverage",
@@ -891,7 +938,7 @@
                 "testing",
                 "xunit"
             ],
-            "time": "2015-10-06T15:47:00+00:00"
+            "time": "2015-10-06 15:47:00"
         },
         {
             "name": "phpunit/php-file-iterator",
@@ -938,7 +985,7 @@
                 "filesystem",
                 "iterator"
             ],
-            "time": "2016-10-03T07:40:28+00:00"
+            "time": "2016-10-03 07:40:28"
         },
         {
             "name": "phpunit/php-text-template",
@@ -979,7 +1026,7 @@
             "keywords": [
                 "template"
             ],
-            "time": "2015-06-21T13:50:34+00:00"
+            "time": "2015-06-21 13:50:34"
         },
         {
             "name": "phpunit/php-timer",
@@ -1028,7 +1075,7 @@
             "keywords": [
                 "timer"
             ],
-            "time": "2017-02-26T11:10:40+00:00"
+            "time": "2017-02-26 11:10:40"
         },
         {
             "name": "phpunit/php-token-stream",
@@ -1077,7 +1124,7 @@
             "keywords": [
                 "tokenizer"
             ],
-            "time": "2017-02-27T10:12:30+00:00"
+            "time": "2017-02-27 10:12:30"
         },
         {
             "name": "phpunit/phpunit",
@@ -1149,7 +1196,7 @@
                 "testing",
                 "xunit"
             ],
-            "time": "2017-02-06T05:18:07+00:00"
+            "time": "2017-02-06 05:18:07"
         },
         {
             "name": "phpunit/phpunit-mock-objects",
@@ -1205,7 +1252,7 @@
                 "mock",
                 "xunit"
             ],
-            "time": "2015-10-02T06:51:40+00:00"
+            "time": "2015-10-02 06:51:40"
         },
         {
             "name": "satooshi/php-coveralls",
@@ -1263,7 +1310,7 @@
                 "github",
                 "test"
             ],
-            "time": "2016-01-20T17:35:46+00:00"
+            "time": "2016-01-20 17:35:46"
         },
         {
             "name": "sebastian/comparator",
@@ -1327,7 +1374,7 @@
                 "compare",
                 "equality"
             ],
-            "time": "2017-01-29T09:50:25+00:00"
+            "time": "2017-01-29 09:50:25"
         },
         {
             "name": "sebastian/diff",
@@ -1379,7 +1426,7 @@
             "keywords": [
                 "diff"
             ],
-            "time": "2015-12-08T07:14:41+00:00"
+            "time": "2015-12-08 07:14:41"
         },
         {
             "name": "sebastian/environment",
@@ -1429,7 +1476,7 @@
                 "environment",
                 "hhvm"
             ],
-            "time": "2016-08-18T05:49:44+00:00"
+            "time": "2016-08-18 05:49:44"
         },
         {
             "name": "sebastian/exporter",
@@ -1496,7 +1543,7 @@
                 "export",
                 "exporter"
             ],
-            "time": "2016-06-17T09:04:28+00:00"
+            "time": "2016-06-17 09:04:28"
         },
         {
             "name": "sebastian/global-state",
@@ -1547,7 +1594,7 @@
             "keywords": [
                 "global state"
             ],
-            "time": "2015-10-12T03:26:01+00:00"
+            "time": "2015-10-12 03:26:01"
         },
         {
             "name": "sebastian/recursion-context",
@@ -1600,7 +1647,7 @@
             ],
             "description": "Provides functionality to recursively process PHP variables",
             "homepage": "http://www.github.com/sebastianbergmann/recursion-context",
-            "time": "2016-10-03T07:41:43+00:00"
+            "time": "2016-10-03 07:41:43"
         },
         {
             "name": "sebastian/version",
@@ -1635,7 +1682,7 @@
             ],
             "description": "Library that helps with managing the version number of Git-hosted PHP projects",
             "homepage": "https://github.com/sebastianbergmann/version",
-            "time": "2015-06-21T13:59:46+00:00"
+            "time": "2015-06-21 13:59:46"
         },
         {
             "name": "symfony/config",
@@ -1691,7 +1738,7 @@
             ],
             "description": "Symfony Config Component",
             "homepage": "https://symfony.com",
-            "time": "2017-04-04T15:30:56+00:00"
+            "time": "2017-04-04 15:30:56"
         },
         {
             "name": "symfony/console",
@@ -1754,7 +1801,7 @@
             ],
             "description": "Symfony Console Component",
             "homepage": "https://symfony.com",
-            "time": "2017-04-04T14:33:42+00:00"
+            "time": "2017-04-04 14:33:42"
         },
         {
             "name": "symfony/debug",
@@ -1811,7 +1858,7 @@
             ],
             "description": "Symfony Debug Component",
             "homepage": "https://symfony.com",
-            "time": "2017-03-28T21:38:24+00:00"
+            "time": "2017-03-28 21:38:24"
         },
         {
             "name": "symfony/event-dispatcher",
@@ -1871,7 +1918,7 @@
             ],
             "description": "Symfony EventDispatcher Component",
             "homepage": "https://symfony.com",
-            "time": "2017-04-03T20:37:06+00:00"
+            "time": "2017-04-03 20:37:06"
         },
         {
             "name": "symfony/filesystem",
@@ -1920,7 +1967,7 @@
             ],
             "description": "Symfony Filesystem Component",
             "homepage": "https://symfony.com",
-            "time": "2017-03-26T15:47:15+00:00"
+            "time": "2017-03-26 15:47:15"
         },
         {
             "name": "symfony/polyfill-mbstring",
@@ -1979,7 +2026,7 @@
                 "portable",
                 "shim"
             ],
-            "time": "2016-11-14T01:06:16+00:00"
+            "time": "2016-11-14 01:06:16"
         },
         {
             "name": "symfony/stopwatch",
@@ -2028,7 +2075,7 @@
             ],
             "description": "Symfony Stopwatch Component",
             "homepage": "https://symfony.com",
-            "time": "2017-02-18T17:28:00+00:00"
+            "time": "2017-02-18 17:28:00"
         },
         {
             "name": "symfony/yaml",
@@ -2083,7 +2130,7 @@
             ],
             "description": "Symfony Yaml Component",
             "homepage": "https://symfony.com",
-            "time": "2017-03-20T09:45:15+00:00"
+            "time": "2017-03-20 09:45:15"
         },
         {
             "name": "webmozart/assert",
@@ -2133,7 +2180,7 @@
                 "check",
                 "validate"
             ],
-            "time": "2016-11-23T20:04:58+00:00"
+            "time": "2016-11-23 20:04:58"
         }
     ],
     "aliases": [