Placeholder specs for soft-delete behaviour
Refactor handler based scopes etc on route model.

Look Ma, metaprogramming.
Soft-delete routes.

When a route is requested to be deleted, convert it into a gone route unless it has a parent prefix route.
When creating a prefix route, cleanup any child gone routes.
Fix has_parent_prefix_routes? for / edge case
Merge pull request #26 from alphagov/soft_delete

Soft delete of routes.