This is enough to update a notification in DB:
1. First create a notification in the UI and sent it.
2. Then reset its attributes to pretend it's for Reach.
update notifications set
sent_at = null,
sent_by = null,
notification_status='sending'
where id='some-uuid';
3. Change "notification_id" to "<some-uuid>" in the code.
4. Call the boilerplate endpoint for Reach callbacks.
curl -X POST localhost:6011/notifications/sms/reach
Interestingly there's no foreign key constraint on "sent_by" in the
DB, so this just works: the notification is updated.
These were hard to find by searching as the filename doesn't refer
to SMS or letters. Ideally our tests should be organised to reflect
the structure of files in app/, so this does that.
