Moved vfs stream wrapper to dev dependencies

Author: micha149

composer.json

@@ -12,9 +12,11 @@
     ],
     "require": {
         "php": ">=5.3.0",
-        "mikey179/vfsStream": "1.1.*",
         "symfony/http-foundation": ">=2.1"
     },
+    "require-dev": {
+        "mikey179/vfsStream": "1.1.*"
+    },
     "autoload": {
         "psr-0": { "Brainbits": "src/" }
     },