(PUP-2913) Remove RGen

With https://tickets.puppetlabs.com/browse/PUP-2914, it was decided to vendor
rgen into puppet codebase to affect the least number of users. Due to this we
no longer need to vendor an additional RGen package in Puppet-Win32-Ruby.
Merge pull request #62 from ferventcoder/ticket/2.0.0-x64/PUP-2913-remove-rgen

(PUP-2913) Remove RGen