Build and run tests on GitHub-hosted runners

A GitHub-hosted runner is a virtual machine hosted by GitHub with the GitHub
Actions runner application installed.

.github/workflows/ant.yml

@@ -0,0 +1,21 @@
+name: Java CI
+
+on: [push]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up JDK 1.8
+      uses: actions/setup-java@v1
+      with:
+        java-version: 1.8
+    - name: Build with Ant
+      working-directory: ./build
+      run: ant clean dist
+    - name: Run tests
+      working-directory: ./app
+      run: ant test