Doesn't work with JRuby 10.1.1.0

JRuby 10.1.1.0 deprecated the jruby-complete artifact. I guess that's the reason I get:

Execution failed for task ':features:gemPrepareRubocop' (registered in build file 'features/build.gradle').
> Location of jruby-complete is not set.

After updating to JRuby 10.1.1.0.

cc @ysb33r