Add extras packages to rpmbuilder, and add bundler

This commit adds extras packages to the rpm-builder module, and includes
bundler in them!

Signed-off-by: Moses Mendoza <moses@puppetlabs.com>
Default to false for extra packages
Merge pull request #20 from MosesMendoza/add_bundler_and_extras

Add extras packages to rpmbuilder, and add bundler