Tiny bootstrap helper to get new users started with hacken.in #394

This (not so tiny) change will move everything Vagrant-related to a
separate folder /vagrant and bootstrap a smaller Gemset from there, so
users without PostgresSQL header files can also give hacken.in a try. :D
Merge pull request #464 from hacken-in/394-bootstrap-script

Tiny bootstrap helper to get new users started with hacken.in #394