Add integration test

.github/workflows/autobump.yml

@@ -0,0 +1,31 @@
+name: autobump
+on:
+  schedule:
+    - cron:  '*/15 * * * *'
+  pull_request: # for testing
+
+jobs:
+  autobump:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ./
+        id: autobump
+        with:
+          file: testdata/testfile
+          version_name: REVIEWDOG_VERSION
+          repo: reviewdog/reviewdog
+
+      - name: Create Pull Request
+        uses: peter-evans/create-pull-request@v2
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          title: "chore(deps): update reviewdog to ${{ steps.autobump.outputs.latest }}"
+          commit-message: "chore(deps): update reviewdog to ${{ steps.autobump.outputs.latest }}"
+          body: |
+            Update reviewdog to [${{ steps.autobump.outputs.latest }}](https://github.com/reviewdog/reviewdog/releases/tag/${{ steps.autobump.outputs.latest }})
+
+            This PR is auto generated by [autobump workflow](https://github.com/${{ github.repository }}/actions?query=workflow%3Aautobump).
+          branch: autobump/reviewdog
+
+