Add upstream reference to git push command

package.json

@@ -22,7 +22,7 @@
         "create-theme": "node ./scripts/create-theme.js",
         "build": "node ./scripts/build.js",
         "version": "git checkout -b release/$npm_package_version && npm run build && git add -A",
-        "postversion": "git push && git push --tags && git checkout master"
+        "postversion": "git push -u origin release/$npm_package_version && git push --tags && git checkout master"
     },
     "author": "Mauricio Bonani @mbonani",
     "funding": {