Added GitHub CI workflow

.github/workflows/bld.yml

@@ -0,0 +1,26 @@
+name: bld-ci
+
+on: [push, pull_request, workflow_dispatch]
+
+jobs:
+  build-gradle-project:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        java-version: [ 17, 20 ]
+
+    steps:
+      - name: Checkout source repository
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+
+      - name: Set up JDK ${{ matrix.java-version }}
+        uses: actions/setup-java@v3
+        with:
+          distribution: 'temurin'
+          java-version: ${{ matrix.java-version }}
+
+      - name: Run tests
+        run: ./bld download compile test