[ci] run maven Java unit tests

Author: kares

.github/workflows/ci-test.yml

@@ -76,5 +76,8 @@ jobs:
       - name: rake test_prepare
         run: jruby -rbundler/setup -S rake test_prepare
 
+      - name: mvn test
+        run: ./mvnw test
+
       - name: rake test
         run: jruby -rbundler/setup -S rake test