Request for Comment: Support multiple moduledirs in a Puppetfile

This is for discussion purposes.

Here is one possible way of doing multiple `moduledirs` in a Puppetfile.  I coded this to work with `r10k deploy environment -p`

Example Puppetfile:

    moduledir 'my_modules'
    
    mod 'lvm',
      :git => 'https://github.com/puppetlabs/puppetlabs-lvm.git',
      :moduledir => 'puppetlabs'

    mod 'r10k',
      :git => 'https://github.com/adrienthebo/r10k.git'