Move generator into the upstream Kibana repo?

[rashidkpc]

Right now its challenging to version this, maybe we should move it into the Kibana repo itself?

[kimjoar]

+1. I like the way babel does this using a mono-repo approach (https://github.com/babel/babel/tree/master/packages). It's got a packages folder with all the different npm packages, then a script to release them.