Dropping dependency versions

composer.json

@@ -14,10 +14,10 @@
     "minimum-stability": "stable",
     "require": {
         "php": ">=5.3.0",
-        "symfony/config": "~3.0",
-        "symfony/dependency-injection": "~3.0",
-        "symfony/filesystem": "~3.0",
-        "symfony/yaml": "~3.0",
+        "symfony/config": "~2.3",
+        "symfony/dependency-injection": "~2.3",
+        "symfony/filesystem": "~2.3",
+        "symfony/yaml": "~2.3",
         "twig/twig": "~1.16",
         "jakoch/phantomjs-installer": "2.0.0"
     },