Managing rake and bundler packages. Rake and bundle resources.

This is a work in progress, I've made the PR early in order to collect comments and suggestions.

The intention is to have the ruby module manage the installation of the rake and bundle tools, and provide resources for executing rake and bundler tasks. It's a bit hard to do rake and bundle tasks in the abstract without having specific knowledge of how bundler or rake are installed, e.g. you need to make the `require` OS specific for the bundler package... which will fail if they were installed by a virtual package.
is there really no better way in puppet to do this other than a big `if`/`else` which calls pretty much the exact same options on two different things…?