Description:
============
    Stubs out a new messenger and its views. Passes the messenger name,
    either CamelCased or under_scored, and an optional list of messengers as arguments.

    This generates a messenger class in app/messengers and invokes your template
    engine and test framework generators.

Example:
========
    rails generate messenger Account registerd_notify

    creates a Account messenger class, views, and test:
        Messenger:  app/messengers/account_messenger.rb
        Views:      app/views/account_messengers/registerd_notify.text.erb