CouchElephant 1.3.1

Fixed

• Upgrading to 1.3.0 announced bookings that had already been announced.
  1.3.0 re-keys existing bookings onto the new airing id. The alert state is
  keyed on that same id, and it was not re-keyed with them, so the next
  dispatch read a booking nobody had heard about and said so again. Seen on a
  live install: two recordings booked days earlier were announced a second time
  at the moment of the upgrade.

  The whole rule notify_state runs on is that a row exists means this
  destination has been told, and the migration broke the key that rule depends
  on. Both are now re-keyed together, state first.

  Nothing was booked twice and no recording was affected. Only the messages
  were duplicated.