model_spec is far too long, let's break it up into specs for individual
models in the dummy app.
Extract spec/models/legacy_widget_spec.rb
Extract spec/models/on/empty_array_spec.rb
Extract spec/models/on/create_spec.rb
Extract spec/models/on/update_spec.rb
Extract spec/models/on/destroy_spec.rb
Move an example to config_spec.rb
Extract spec/models/translation_spec.rb
Extract spec/models/article_spec.rb
Move examples to document_spec.rb
