bump surefire/testng version
bump surefire/testng version

Although TestNG is still in beta, it seems to fix an issue we are affected by: using "dependsOnMethods" in hierarchies of tests previously skipped some executions of methods. This is not the case with the new version.

LearnLib/automatalib,misberner/automatalib,LearnLib/automatalib,misberner/automatalib,LearnLib/automatalib,LearnLib/automatalib