Overhaul ansible playbook and Vagrantfile for 3.0
This isn't complete, largely because pulp's own 3.0-dev branch isn't
itself complete (we haven't yet removed all subpackages provided in
pulp 2, plugins aren't converted to pulp 3 yet, etc.).
The vagrant setup script has been destroyed, and its functionality
has been implemented in ansible. The ansible pulp_facts module has
been significantly improved, and should be much easier to maintain
by (and be in general less scary to) Pulp developers in general.
Additionally, support for the pulpproject.org repository has been
added (ruby deps are installed, and bundler is run on that repo's