Allow symfony/symfony 2.5 and 2.6

Author: ricbra

composer.json

@@ -15,7 +15,7 @@
     "minimum-stability": "dev",
     "require": {
         "php": ">=5.3.3",
-        "symfony/symfony": "2.5.*",
+        "symfony/symfony": "~2.5,<2.7",
         "doctrine/orm": "~2.2,>=2.2.3",
         "doctrine/doctrine-bundle": "~1.2"
     },