Added GitHub Actions CI

.github/workflows/maven.yml

@@ -0,0 +1,25 @@
+name: maven
+
+on:
+  push:
+    branches: [ master ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        java: [ 8, 11, 17 ]
+
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-java@v1
+      with:
+        java-version: ${{ matrix.java }}
+    - uses: actions/cache@v2
+      with:
+        path: ~/.m2
+        key: ${{ runner.os }}-m2-${{ hashFiles('**/pom.xml') }}
+        restore-keys: ${{ runner.os }}-m2
+    - run: mvn -B package --file pom.xml