First cut at using Vagrant for development

I imported and adapted the Vagrantfile and provisioning shell script
from Agile Ventures Local Support. The provisioning script imports the
generic Rails script from AgileVentures/setup-scripts.

This is held together with duct tape and string, but it works, so it is
ready for others to try out. Then we can make improvements based on
experience.

To use it, [install Virtual Box](https://www.virtualbox.org/wiki/Downloads) , then the usual
incantation:
1. `cd WebsiteOne`
2. `vagrant up`
3. `vagrant ssh`
To keep the shared folder (`/WebsiteOne` on the guest) in sync, open a new terminal
and run `vagrant rsync-auto`.