Use ENV variables for configuration.

* Use ENV variables with magiconf configuration
* Use dotenv (https://github.com/bkeepers/dotenv) for setting ENV variables locally
* Remove the application.example.yml in favor of a .env.example
* Updates the README to explain that dotenv is now being used

Pivotal Tracker ID: 64152486
Add Foreman.

Foreman handles Profile based application management. Boot up the application
with:

foreman start

It currently only boots up the Rails application.
Merge pull request #48 from opscode/64152486-use-env-variables

Use ENV variables for configuration.