I'm seeing an error related to this:
`"NameError in MappingsController#update
uninitialized constant Transition::OffSiteRedirectChecker
Rails.root: /var/govuk/transition
Application Trace | Framework Trace | Full Trace
app/controllers/mappings_controller.rb:93:in update'"`

Does this controller also need:
`require 'transition/off_site_redirect_checker'`

Weirdly the tests are all passing.