[#666] Including a Vagrant setup

This Vagrant setup uses Ansible as provisioner, and a Ubuntu 14.04 base box. Using NFS for shared folders, as it provides better performance.

It was tested with a Ubuntu 14.04 Host machine. If someone could test it on OSX, that would be great!

Instructions were included in the CONTRIBUTING and Readme files. For now, you'll need to login to run `rails s` after provisioning the server. We thought this would be better for development, since it provides more rich debug information.

The content of the file is totally fine, I am just picking in the indentation. You used 4 spaces indentation, and usually we use 2 spaces to indent ruby files.