cleanups to rails 3 boot process

fixes #1254 - initial support to pxeboot windows

since travis use rvm and we don't want puppet gem in our gem file..

debian platform puppet is still considered a as a gem

ensure that bundler loads after our custom gem requirements

ensures that puppet packages are installed in our CI

removed puppet from Gem file requirement

this commit also tries to simplify the way we use bundler, in future commits,
we should add more logic of which gems to load based on configration file.

make sure foreman doesnt blow up when running without libvirt / virt gems

ensure facts importer works correctly also when importing from a report / rake task

ensures populate hosts rake task can run correctly