After following the POM updates in the linked blog update, try the following maven commands:
$ mvn clean package -DskipTests
$ mvn test
IIRC I would occasionally run into this issue if the OSGi SCR metadata XML files weren't generated when the tests ran; doing the `mvn clean package` would generate this for me and then allow my tests to run (you could try dialing it back to `mvn clean compile` or other phases/goals)