add github action for build

.github/workflows/build.yml

@@ -0,0 +1,20 @@
+name: build
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Set up Java
+        uses: actions/setup-java@v1
+        with:
+          java-version: 8
+      - name: Build with Maven
+        run: mvn --batch-mode --update-snapshots verify