Added branch name to PR job

Author: Voffkaa

lib/webhooks.js

@@ -117,7 +117,8 @@ function pullRequestJob(pr) {
     trigger: trigger,
     deploy: false,
     ref: {
-      fetch: 'refs/pull/' + pr.number + '/merge'
+      fetch: 'refs/pull/' + pr.number + '/merge',
+      branch: pr.base.ref
     },
     plugin_data: {
       github: {