Add Vagrantfile and Chef recipes to setup development environment for Purpose.

See comments at the top of Vagrantfile for usage. Summary:

   Install VirtualBox and vagrant (vagrantup.com).
   - Tested with vagrant 1.1.5 and VB 4.2.10
   vagrant up  (...wait while stuff happens...)
   vagrant ssh
   cd /platform
   foreman start -f Platform.dev
   Visit localhost:5000 in your web browser.
Allow user specific additions to .env

If you create a env.local file it will be appended to the .env created
by the Vagrant recipe. env.local is in the .gitignore
Merge pull request #1 from fightforthefuture/wip-vagrant-chef

Vagrant/chef configuration for a development environment