Incorrect Function Definition in Publish

When [connection.publish](https://github.com/jmanero/nsq-client/blob/master/lib/connection.js#L84) is called it passes the topic and message incorrectly to [protocol.publish](https://github.com/jmanero/nsq-client/blob/master/lib/connection/protocol.js#L188)

The [documentation](https://github.com/jmanero/nsq-client#connection) states that the message should come first, so the function definition needed to be changed.