add workflow

.github/workflows/autopublish.yml

@@ -0,0 +1,17 @@
+name: Publish package to GitHub Packages
+on:
+  release:
+    types: [created]
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-java@v1
+        with:
+          java-version: 1.8
+      - name: Publish package
+        run: ./gradlew publishAllPublicationsToGithubPackagesRepository
+        env:
+          GITHUBPACKAGES_USER: ${{ secrets.GITHUBPACKAGES_USER }}
+          GITHUBPACKAGES_PASSWORD: ${{ secrets.GITHUB_TOKEN }}