Updated the constraints to allow Symfony 2.3

Closes #1107
Closes #1085

Author: stof

composer.json

@@ -22,9 +22,9 @@
     "minimum-stability": "dev",
     "require": {
         "php": ">=5.3.2",
-        "symfony/framework-bundle": ">=2.1,<2.3-dev",
-        "symfony/form": ">=2.1,<2.3-dev",
-        "symfony/security-bundle": ">=2.1,<2.3-dev"
+        "symfony/framework-bundle": ">=2.1,<2.4-dev",
+        "symfony/form": ">=2.1,<2.4-dev",
+        "symfony/security-bundle": ">=2.1,<2.4-dev"
     },
     "require-dev": {
         "twig/twig": "*",