fixed composer.json

Author: fabpot

src/Symfony/Component/Config/composer.json

@@ -20,7 +20,7 @@
         "symfony/filesystem": "~2.3|~3.0.0"
     },
     "require-dev": {
-        "symfony/yaml": "~2.7"
+        "symfony/yaml": "~2.7|~3.0.0"
     },
     "suggest": {
         "symfony/yaml": "To use the yaml reference dumper"