Composer fix

Author: wouterj

composer.json

@@ -21,7 +21,7 @@
     },
     "require-dev": {
         "symfony-cmf/testing": "1.1.*",
-        "symfony/yaml": "~2.1.0",
+        "symfony/yaml": "~2.1",
         "phpspec/prophecy": "1.1.2",
         "matthiasnoback/symfony-dependency-injection-test": "0.*",
         "matthiasnoback/symfony-config-test": "0.*"