Introduce a Vagrantfile and provision with WSU Web Provisioner

[WSU Web Provisioner](https://github.com/washingtonstateuniversity/wsu-web-provisioner) contains all of the provisioning we need for production and development environments.

WSUWP Platform should include a Vagrantfile that uses `vagrant up` to:

* [x] Retrieve the latest provisioning from WSU Web Serverbase
* [x] Launch Salt with a specific minion configuration
* [x] Map the current working directory to `/srv/www/` inside the VM
* [x] Provide hosts configuration necessary for access to desired sites.