Description:
    The behavior generator creates stubs for a new behavior.

    The generator takes a model name as its argument.  The model name may be
    given in CamelCase or under_score and should not be suffixed with 'Behavior'.

    The generator creates a model class in app/behaviors and a test suite in
    test/unit/behaviors.

Example:
    ./script/generate behavior BookArchive

    This will create a BookArchive behavior:
        Behavior:   app/behaviors/book_archive_behavior.rb
        Test:       test/unit/behaviors/book_archive_behavior_test.rb

