ASync reader

Using someones implementation of an event loop and async streams, create an Asynchronous Client

removes the need for acknowledgement handler (a little bit)

```php
interface AsyncMessageHandler {
public function handle(MessageInterface $message, callable $done) : PromiseInterface
}

class Reader {
public function asyncRead(AsyncMessageHandler $handler, int $num) {
// read
$handler->handle($message, $done)
->then($this->acknowledge, $this->reject);
}
}
```