Use github actions for testing (#597)

For now, this is in addition to travisCI.

Author: lesserwhirls

.github/workflows/tests.yml

@@ -0,0 +1,20 @@
+name: DS3 Java SDK Tests
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up JDK
+        uses: actions/setup-java@v3
+        with:
+          distribution: 'temurin'
+          java-version: '8'
+          cache: 'gradle'
+          check-latest: true
+      - name: Run PR Tests
+        run: ./gradlew -S clean jar :ds3-sdk:test :ds3-utils:test :ds3-metadata:test