IPv6 hostname resolution

[GhostofGoes]

Currently, hostnames only resolve to IPv4 addresses, as documented in the "Known Issues" section in the README. They should be able to resolve to IPv6 addresses as well as IPv4, and the IPv6 returns handled by the appropriate IPv6 logic in getmac.

The obvious solution is to use socket.getaddrinfo instead of socket.gethostbyname to resolve a hostname to an IP address, it just needs to be implemented and tested.

[stuartmccoll]

Hi :wave:.

I'd like to pick this up, if that's okay?

[GhostofGoes]

Sure, go for it :)