JP Phillips

When attempting to use kuard where `/etc/resolv.conf` contained an IPv6 for the nameserver, it would error when making the DNS query due to [net.Dial](https://pkg.go.dev/net#Dial) expecting the IP to be surround...

implements the NACK command as documented in the [disque API](https://github.com/antirez/disque#nack-job-id--job-id)

implements the `SHOW` command as documented in the [disque API](https://github.com/antirez/disque#show-job-id)