title: Sidekiq/Airbrake only post exception when retries extinguished
body: <p>I would like Airbrake to only be notified of errors when the retries are exhausted, but I can't seem to think of a way to implement it...</p>
  
  <p>I can add a sidekiq_retries_exhausted hook to send the error to AirBrake but the only way I can think of catching the actual failures is to add a middleware that swallows the error, but then, the job will be marked as a success if there is no error... then there will never be any retries..</p>
  
  <p>Hope that makes sense!</p>