How to use an broker SRV record to connect?

Hi,

I am trying to connect to my broker running at `_mqtt._tcp.iot.domain.com` but it is failing with
```sh
(node:296427) UnhandledPromiseRejectionWarning: Error: getaddrinfo ENOTFOUND _mqtt._tcp.iot.domain.com
```
I verified with a dig that I am able to get the SRV record.