Merge pull request #192 from GrahamCampbell/patch-2

Make the next release 2.2.0

Author: dbu

composer.json

@@ -61,7 +61,7 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-master": "2.1.x-dev"
+            "dev-master": "2.2.x-dev"
         }
     }
 }