Rolling RC for ratis-thirdparty

[Josh Elser]

(Finally) Pushed RATIS-335 to pull Hadoop shading into the thirdparty 
repo. Pushed a new SNAPSHOT build to asf nexus which should prevent any 
build-related errors (if you see something, make sure you rebase/merge 
ratis.git on top of master and/or use `mvn -U` to force a SNAPSHOT refresh).

AFAIK, we're good for a thirdparty release and will start working on an 
RC. Shout if there's anything you notice that needs to be fixed prior.

Thanks!