Restore branch alias (this is still dev and not yet moved to a numbered branch).

Author: judgej

composer.json

@@ -32,5 +32,10 @@
     },
     "require-dev": {
         "omnipay/tests": "~2.0"
+    },
+    "extra": {
+        "branch-alias": {
+          "dev-master": "2.0.x-dev"
+        }
     }
 }