Merge branch '3.0.x' into feature/UIMA-6009-Use-Maven-dependency-plugin-to-check-dependencies-3_0_x

* 3.0.x:
  Remove redundant declaration of Java target and source version. In the v2 branch, this is necessary because the benchmarking module requires Java 8, but in the v3 branch, Java 8 is the standard anyway.