Re-write "creating an app" feature spec with capybara rspec.
Re-write "n+1 query insight" spec with capybara rspec.
Re-write "send email asynchronously insight" spec with capybara rspec.
Re-write "sign in" spec with capybara rspec.
Re-write "sign out" spec with capybara rspec.
Re-write "sign up" spec with capybara rspec.
Remove turnip gem.
Don't require capybara unless requested.