new: GitHub Actions

.github/workflows/build.yml

@@ -0,0 +1,30 @@
+name: build
+on: [pull_request, push]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: checkout repository
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+
+      - uses: actions/cache@v3
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: ${{ runner.os }}-gradle0-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}
+          restore-keys: |
+            ${{ runner.os }}-gradle0-
+      - name: validate gradle wrapper
+        uses: gradle/wrapper-validation-action@v1
+      - name: setup jdk 17
+        uses: actions/setup-java@v3
+        with:
+          distribution: 'zulu'
+          java-version: 17
+          java-package: jdk
+      - name: build
+        run: ./gradlew build