I think I've completed what I wanted to do for the dorab-vagrant branch. It now loads the basic packages on the instance, sets up users to be able to log in via ssh and hardens the sshd. Would someone please review and merge into master if deemed appropriate. Thanks.

Next, I'm looking into plexus/ansible_playbooks and seeing what I need to do to move it over to the nebula repo. I'll make a new branch for that work.