Release out of vX.Y branches

Author: AArnott

src/version.json

@@ -6,7 +6,7 @@
   },
   "publicReleaseRefSpec": [
     "^refs/heads/master$", // we release out of master
-    "^refs/tags/v\\d+\\.\\d+" // we also release tags starting with vN.N
+    "^refs/heads/v\\d+\\.\\d+$" // we also release vX.Y branches
   ],
   "cloudBuild": {
     "buildNumber": {