add release action

.github/workflows/release.gradle.yml

@@ -0,0 +1,43 @@
+on:
+  push:
+    # Sequence of patterns matched against refs/tags
+    tags:
+      - 'v*' # Push events to matching v*, i.e. v1.0, v20.15.10
+
+name: Upload Release Asset
+
+jobs:
+  build:
+    name: Upload Release Asset
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+      - name: Set up JDK 1.8
+          uses: actions/setup-java@v1
+          with:
+            java-version: 1.8
+            - name: Grant execute permission for gradlew
+              run: chmod +x gradlew
+            - name: Build with Gradle
+              run: ./gradlew release
+      - name: Create Release
+        id: create_release
+        uses: actions/create-release@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          tag_name: ${{ github.ref }}
+          release_name: Release ${{ github.ref }}
+          draft: false
+          prerelease: false
+      - name: Upload Release Asset
+        id: upload-release-asset
+        uses: actions/upload-release-asset@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          upload_url: ${{ steps.create_release.outputs.upload_url }} # This pulls from the CREATE RELEASE step above, referencing it's ID to get its outputs object, which include a `upload_url`. See this blog post for more info: https://jasonet.co/posts/new-features-of-github-actions/#passing-data-to-future-steps
+          asset_path: ./build/distributions/openTCS-4.18.0-SNAPSHOT-bin.zip
+          asset_name: openTCS-4.18.0-SNAPSHOT-bin.zip
+          asset_content_type: application/zip