Note for myself:
In case you get such error
java.lang.IllegalStateException: Test runner could not locate test class [org.jboss.windup.addon.ui.WindupUpdateDistributionCommandXTest] in any deployed Addon - Reason unknown.
It's because the test is using a simple Furnace container by default, and you rather need the CDI container, i.e.
@AddonDependency(name = "org.jboss.forge.furnace.container:cdi"),
Would be nice if Furnace told you something along the lines of "You are using the simple container, that means services should be registered as documented at http://..."