ci: Setup GitHub actions for basic PR CI matrix build

.github/workflows/maven-ci.yml

@@ -0,0 +1,66 @@
+# This workflow will build a Java project with Maven
+# For more information see: https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-maven
+
+name: CI
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        # 15 and 16 not supported yet - test failures - see https://github.com/ronmamo/reflections/pull/332
+        java: [ '8', '9', '11', '13']
+        # doesn't work on Windows yet - see https://github.com/ronmamo/reflections/pull/331
+        os: [ ubuntu-latest ]
+    name: Java ${{ matrix.Java }} on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Setup Java
+        uses: actions/setup-java@v2
+        with:
+          distribution: 'adopt'
+          java-version: ${{ matrix.java }}
+
+      - name: Show java 13 home
+        run: which java
+
+      - name: Show java version
+        run: java -version
+
+      - name: Show mvn version
+        run: mvn -version
+
+      - name: Cache Maven packages
+        uses: actions/cache@v1
+        with:
+          path: ~/.m2/repository
+          key: ${{ runner.os }}-m2
+          restore-keys: ${{ runner.os }}-m2
+
+      - name: Test with Maven
+        run: mvn -Pci -B clean package ${{ matrix.jdk }}
+
+#     - name: Archive test results
+#       if: ${{ always() }}
+#       uses: actions/upload-artifact@v2
+#       with:
+#         name: test-reports
+#         path: target/**-reports/*
+#         retention-days: 14
+#
+#     - name: Archive surefire test results
+#       if: ${{ always() }}
+#       uses: actions/upload-artifact@v2
+#       with:
+#         name: test-reports
+#         path: target/surefire-reports/*
+#         retention-days: 14