Allow private domains

[adrukh]

Right now, toRegistrableDomain() uses ICANN-only parsing:

toRegistrableDomain('username.github.io') // returns 'github.io', expected 'username.github.io'

Would you be open to support private registrable domains, i.e. exposing tldts's allowPrivateDomains option?

My workaround for now is to rely on tldts for domain parsing, and rdapper only for the lookup. Would love to save the duplication :)

[adrukh]

Thanks for addressing! Am I right to assume b171b5e handles this?

[adrukh]

I got back to this issue as I was trying to get rdapper to properly lookup itnext.co.ua.

1. Performing a basic whois lookup goes to whois.ua, since in ICANN notation, the base tld for this domain is ua. whois.ua rejects this request.
2. If we parse the domain relying on PSL (ICANN+Private), we see that the tld is co.ua. Performing a whois lookup against whois.co.ua results in proper data.
3. So we simply need to tell rdapper to use whois.co.ua as a whoisHint! But the way this is passed via the options object makes me coerce the hint, and use { 'ua': 'whois.co.ua' } instead of { 'co.ua': 'whois.co.ua' }. The former option helps rdapper complete the lookup successfully. But it is misleading, since whois.co.ua isn't at all authoritative for the ua tld...

Maybe, if we only perform one lookup at a time, we can provide a whois hint without specifying the tld it should be used for? Or maybe there is a better solution. Or maybe this isn't even a problem?