Added release commands
Removed url parameter from Release#add
docs > parser
Just run the command directly, no need for an Application class
Added highline as a dependency
Simplified Helpers#current_app_name

Currently app name look up works as the following:
first check the options for a :app, next try the ENV variable DAWN_APP,
else check the Dawn::CLI.selected_app else try to determine the app by extracting information from git.
Otherwise, the app could not be found.
App#scale does not require an `app` paramter
Added Dawn::CLI.selected_app
Set selected_app from the `--app` option
Do not echo password input
Completed commands