Change pipeline to trigger only on master

bitbucket-pipelines.yml

@@ -6,13 +6,14 @@
 image: python:3.5.1
 
 pipelines:
-  default:
-    - step:
-        # set HEROKU_API_KEY and HEROKU_APP_NAME environment variables
-        # set clone `depth: full' as described here: https://confluence.atlassian.com/x/Y9-5Mw
-        name: Deploy to Heroku staging
-        deployment: staging   # set to test, staging or production
-        # trigger: manual  # uncomment to have a manual step
-        script:
-          - git push https://heroku:$HEROKU_API_KEY@git.heroku.com/$HEROKU_APP_NAME.git HEAD
+  branches:
+    master:
+      - step:
+          # set HEROKU_API_KEY and HEROKU_APP_NAME environment variables
+          # set clone `depth: full' as described here: https://confluence.atlassian.com/x/Y9-5Mw
+          name: Deploy to Heroku staging
+          deployment: staging   # set to test, staging or production
+          # trigger: manual  # uncomment to have a manual step
+          script:
+            - git push https://heroku:$HEROKU_API_KEY@git.heroku.com/$HEROKU_APP_NAME.git HEAD