Add GitHub Actions build.yml to run Maven in CI

Author: sideshowbarker

.github/workflows/build.yml

@@ -0,0 +1,28 @@
+name: Build
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        java: [8, 11, 14]
+        os: [ubuntu-latest, macos-latest, windows-latest]
+    name: Java ${{ matrix.java }}
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          submodules: true
+      - name: Set up java
+        uses: actions/setup-java@v1
+        with:
+          java-version: ${{ matrix.java }}
+      - name: Cache Maven packages
+        uses: actions/cache@v2
+        with:
+          path: ~/.m2
+          key: ${{ runner.os }}-m2-${{ hashFiles('**/pom.xml') }}
+          restore-keys: ${{ runner.os }}-m2
+      - name: Build with Maven
+        run: mvn -B package