composer.json: branch-alias v3.1 branch as v3.1.x-dev; master as v3.2.x-dev

Author: ek9

composer.json

@@ -51,7 +51,8 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-master": "3.1.x-dev"
+            "dev-master": "3.2.x-dev",
+            "dev-v3.1": "3.1.x-dev"
         }
     }
 }