message: recover from pub errors
diff: @@ -51,6 +51,8 @@ func (p *GooglePublisher) Publish(ctx context.Context, msg []byte) error {
  Data: msg,
  OrderingKey: messageOrderingKey,
  }
  + // If there was an error previously, clear it out to allow publishing to work again
  + p.topic.ResumePublish(messageOrderingKey)
  result := p.topic.Publish(ctx, &pmsg)
  _, err := result.Get(ctx)
  return err
  