Fix visit controller spec with 3 slots
Added another domain.
Move done page link to confirmation page
Highpoint North and South can book a visit on the next day.

[Finishes #79962166]
Merge pull request #61 from ministryofjustice/move-feedback

Move done page link to confirmation page
Updated copy for for date to be inserted

Instead of saying '3 working days' before users can expect a reply, we are calculating the actual date that they'll hear back by. Hopefuly this will cut down on requests from visitors.

@janszumiec to update the code