Add Vagrant back as a development option
The old vagrant installation installed the cookbook as the git user instead of the vagrant user. This caused many unforseen problems and we removed this in #51 (closed)
But to make development easier and possible on OSX we should bring it back.
See community demand in:
We're accepting merge requests for adding a Vagrantfile to this cookbook-gitlab repository that will use the cookbook to install it under the vagrant user.
/cc @marin @dblessing