Description

During the investigation of #2429 I noticed that some tests are not executed. It seems that surefire is currently configured with <groups>unit</groups>, so it will only execute tests that explicitly set the group with @Test(groups = {"unit"}). However, there are a lot of tests that are just plain @Test (e.g. here). These are neither picked up by the integration tests nor by the unit tests.

Steps to reproduce

1. Look for a test with @Test
2. Modify it to fail
3. Run mvn verify
4. Observe that all tests are green

Expected Behaviour

Step 3 should pick up the modified test and report its failure.