Organizing by model has its disadvantages, but it's at least
an easy scheme to understand.
Extract spec/models/foo_widget_spec.rb
Extract spec/models/wotsit_spec.rb
Move tests to article_spec.rb
Extract spec/models/book_spec.rb
Move tests to song_spec.rb
Move test to book_spec.rb
Move tests to widget_spec.rb
Jared Beck