Try to not install dev version of 1.1

Author: wouterj

composer.json

@@ -20,7 +20,7 @@
     },
     "require-dev": {
         "symfony-cmf/core-bundle": "~1.1",
-        "symfony-cmf/testing": "~1.1@stable",
+        "symfony-cmf/testing": "~1.1,>=1.1.0",
         "matthiasnoback/symfony-dependency-injection-test": "0.*",
         "matthiasnoback/symfony-config-test": "0.*",
         "sonata-project/doctrine-phpcr-admin-bundle": "~1.1",