Support a string source in the route map
Improvement to https://gitlab.com/gitlab-com/www-gitlab-com/merge_requests/4865, as suggested by @markpundsack
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Improvement to https://gitlab.com/gitlab-com/www-gitlab-com/merge_requests/4865, as suggested by @markpundsack