Re-registers unpublished/archived/deleted editions

Editions which have been archived or unpublished in Whitehall don't have
their state updated in Panopticon.

Story: https://www.pivotaltracker.com/story/show/69528904

This adds the "unpublish" and "archive" verbs to the Panopticon
Registrar service listener and sets the adequate state on the
RegisterableEdition object sent to Panopticon.

This solution also requires updating `edition_test#should_remove_published_edition_from_search_index`
since this now triggers an external request.
Do we need to have this as a data migration? It's easy enough to run the rake task manually from the console. If it's a data migration, then everyone working with whitehall will potentially have to run it, and it not only relies on a running person of panopticon, but will also take a very long time, with no real change to the data on whitehall itself.