Description:
    Stubs out a new observer. Pass the observer name, either CamelCased or
    under_scored, as an argument.

    This generator only invokes your ORM and test framework generators.

Example:
    `rails generate observer Account`

    For ActiveRecord and TestUnit it creates:
        Observer:   app/models/account_observer.rb
        TestUnit:   test/unit/account_observer_test.rb
