Add ability to load Vagrant project.yaml

For Vagrant-based deploys, we want to remove the need to have the
config repo present.

If env.provider_zone contains 'vagrant', load a local project.yaml
file from ./vagrant/project.yaml
re is more a last resort tool for python - thanks for using "a in b"
reg naming - I'd use cotton.yaml instead of project.yaml - otherwise we will get lost later