Description:
Generates a new Coco component with test and preview

Example:
rails generate coco App::Elements::Button

    Creates the component class and associated files
        app/components/coco/app/elements/button/component.rb
        app/components/coco/app/elements/button/component.html.erb
        lookbook/app/previews/app/elements/button_component_preview.rb
        test/components/coco/app/elements/button_component_test.rb