Fix puppetlabs-extras repo issue

The puppetlabs-enterprise-extras repo rpm was not being downloaded
Edited the Rakefile to grab the rpm and the kickstart to use it
Puppet enterprise extras + drop shell

- Take two on enabling the enterprise extras repo :)
- Stop dropping me into a shell at the end.
added .rpm at the end of the rpm file

- Copy and Paste! Don't type, says @acidprime :)
@casharma