Re-registers unpublished/archived/deleted editions

Editions which have been archived or unpublished in Whitehall don't have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.
Would this be clearer as a case statement more like this? The mixture of ternary operator and if statement can get a little confusing

```ruby
case edition.state
when "archived", "deleted"
  "archived"
when "published"
  "live"
...
```