[PR] Improvements toward matching local development with production

* [x] Starts treating the hostname of the dev environment like an ID to match with WSU Web Provisioner's `top.sls`
* [x] Stages provisioning files in a home directory before moving to `/srv/salt/`, something we're likely to do in production
* [x] Grabs the `develop` branch of Salt when installing, as we need it for some MySQL features
* [x] Adds a pillar file for MySQL data with a user and password to be used during provisioning. This will be private in production.