Update the conditional deploy

cloudbuild.yaml

@@ -1,11 +1,11 @@
 # Copyright 2019 Google LLC
-# 
+#
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
-# 
+#
 #     https://www.apache.org/licenses/LICENSE-2.0
-# 
+#
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -13,16 +13,16 @@
 # limitations under the License.
 
 steps:
-  # Generate the website
+  # Generate the website.
   - name: 'gcr.io/gvisor-website/hugo:0.53'
     args: ["make"]
-  # Test the HTML for issues
+  # Test the HTML for issues.
   - name: 'gcr.io/gvisor-website/html-proofer:3.10.2'
     args: ["htmlproofer", "--disable-external", "public/static"]
-  # Deploy to App Engine only for master branch
+  # Deploy to App Engine only for master branch.
   - name: 'gcr.io/cloud-builders/gcloud'
     entrypoint: 'bash'
-    args: 
+    args:
       - '-c'
       - |
-        [[ "$BRANCH_NAME" == "master" ]] && gcloud app deploy public/app.yaml
+        [[ "$BRANCH_NAME" == "master" ]] && gcloud app deploy public/app.yaml || return 0