Add a CI build to autopublish APKs

Author: pimterry

.github/workflows/ci.yml

@@ -0,0 +1,46 @@
+name: CI
+on: [push, pull_request]
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-18.04
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Set up JDK 1.8
+        uses: actions/setup-java@v1
+        with:
+          java-version: 1.8
+
+      - name: Setup Android SDK
+        uses: android-actions/setup-android@v2
+
+      - name: Build release
+        run: ./gradlew assembleRelease
+
+      - uses: actions/upload-artifact@v2
+        with:
+          name: app
+          path: app/build/outputs/apk/release/app-release-unsigned.apk
+          if-no-files-found: error
+
+  deploy:
+    name: Deploy to GitHub Releases
+    needs: build
+    runs-on: ubuntu-18.04
+    if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v')
+    steps:
+      - name: Get the APK
+        id: get_apk
+        uses: actions/download-artifact@v2
+        with:
+          name: app
+
+      - name: Publish the APK to GitHub Releases
+        uses: svenstaro/upload-release-action@v2
+        with:
+          prerelease: true
+          asset_name: pinning-demo.apk
+          file: ${{ steps.get_apk.outputs.download-path }}/app-release-unsigned.apk
+          tag: ${{ github.ref }}
+          repo_token: ${{ secrets.GITHUB_TOKEN }}