Downgrade symfony component to ~2.3, <3.0.0@dev

Author: James Moey

composer.json

@@ -19,11 +19,11 @@
     "require": {
         "php":                      ">=5.4.0",
         "doctrine/common":          "~2.4",
-        "symfony/dependency-injection": "^2.6",
-        "symfony/config": "^2.6",
-        "symfony/http-kernel": "^2.6",
-        "symfony/console": "2.7.*",
-        "symfony/monolog-bundle":   "~2.6"
+        "symfony/dependency-injection": "~2.3, <3.0.0@dev",
+        "symfony/config": "~2.3, <3.0.0@dev",
+        "symfony/http-kernel": "~2.3, <3.0.0@dev",
+        "symfony/console": "~2.3, <3.0.0@dev",
+        "symfony/monolog-bundle":   "~2.3, <3.0.0@dev"
     },
     "require-dev": {
         "phpunit/phpunit":        "~3.7",