Add ci workflow

.github/workflows/ci.yml

@@ -0,0 +1,22 @@
+name: CI
+
+on:
+  workflow_dispatch:
+  push:
+    paths-ignore:
+      - '.github/**'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        java: [ '8', '11', '17' ]
+    name: CI Build ${{ matrix.java }}
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-java@v2
+        with:
+          distribution: adopt
+          java-version: ${{ matrix.java }}
+      - run: ./mvnw -B package