ci: Automerge PR from dependabot (#115)

Author: pankajagrawal16

.github/workflows/build.yml

@@ -41,3 +41,25 @@ jobs:
           java-version: ${{ matrix.java }}
       - name: Build with Maven
         run: mvn -B package --file pom.xml
+
+  auto-merge:
+    runs-on: ubuntu-latest
+    needs: [ build ]
+    if: github.base_ref == 'master' && github.actor == 'dependabot[bot]'
+    steps:
+      - uses: actions/github-script@0.2.0
+        with:
+          script: |
+            github.pullRequests.createReview({
+              owner: context.payload.repository.owner.login,
+              repo: context.payload.repository.name,
+              pull_number: context.payload.pull_request.number,
+              event: 'APPROVE'
+            })
+            github.pullRequests.merge({
+              owner: context.payload.repository.owner.login,
+              repo: context.payload.repository.name,
+              pull_number: context.payload.pull_request.number,
+              merge_method: 'squash'
+            })
+          github-token: ${{ secrets.AUTOMERGE }}