update branch alias for 2.1

Author: cebe

composer.json

@@ -36,7 +36,7 @@
     "bin": ["apidoc"],
     "extra": {
         "branch-alias": {
-            "dev-master": "2.0.x-dev"
+            "dev-master": "2.1.x-dev"
         },
         "asset-installer-paths": {
             "npm-asset-library": "vendor/npm",