Add deploy:<stage> tasks & Deploy staging by default & Refactoring

* Add `deploy:<stage>` tasks
* Deploy staging with default `deploy` task
* Rename `multistage:create_stagefiles` -> `mutistage:init`
* Remove `config/deploy/development.rb` stage file
We can leave out the implementation details of both tasks however as they aren't the focus. I like how you used an ellipse in the deploy task to denote that there was content there.