ci(actions): add auto-merge action

Author: jrolfs

.github/workflows/automerge.yml

@@ -0,0 +1,36 @@
+name: Merge
+on:
+  pull_request:
+    types:
+      - labeled
+      - unlabeled
+      - synchronize
+      - opened
+      - edited
+      - ready_for_review
+      - reopened
+      - unlocked
+  pull_request_review:
+    types:
+      - submitted
+  check_suite:
+    types:
+      - completed
+  status: {}
+jobs:
+  automerge:
+    runs-on: ubuntu-latest
+    steps:
+      - name: automerge
+        uses: 'pascalgn/automerge-action@f81beb99aef41bb55ad072857d43073fba833a98'
+        env:
+          GITHUB_TOKEN: '${{ secrets.GITHUB_TOKEN }}'
+          MERGE_LABELS: 'automerge,!work in progress'
+          MERGE_REMOVE_LABELS: 'automerge'
+          MERGE_METHOD: 'rebase'
+          MERGE_COMMIT_MESSAGE: 'pull-request-description'
+          MERGE_FORKS: 'false'
+          MERGE_RETRIES: '6'
+          MERGE_RETRY_SLEEP: '10000'
+          UPDATE_LABELS: ''
+          UPDATE_METHOD: 'rebase'