v0.5.4

Fixed

• The queue continues past an item that opened no run. A queued plan whose
  whole job is a side effect (a bare mv, a sleep) archives exit_status
  no-run, which execute_queue_loop read as failure and halted on, so a
  batch could not put its sample moves in the queue. item_completed() now
  treats no-run as finished in both the queue loop and
  execute_single_item; plans_failed already excluded it.