Publisher on publish event/hook

Assume you have a publisher that wants to send a message to a work queue, and this publisher is only concerned about the success of the publishing and nothing more. Is this achievable?

I have seen an example hooking into the `drain` event, but this event is only emitted when publishing reaches 0.

Code example:

```JavaScript
rabbitBroker.publish(message, { key: 'somekey' });
rabbitBroker.on('publish', function() { resolve() });
```