add HTTPS support and let'sencrypt cert generation via duckdns

[FrancYescO]

Is still a WIP, i've opened the PR to have some suggestion (sorry for the cascading-promises in lecerts i was just too noob to implement await in coffeescript)

@BoLaMN can you suggest a way to intercept and send our IP to a DNS query via the module you already made?

actual usage:
create and store in key.key and cert.cert file an SSL valid certificate (PC must be online)
--acsurl="https://xxxx.duckdns.org" --certonly --duckdnstoken="xxxx"
than normal start with an server HTTPS server using the stored key.key and cert.cert
--acsurl="https://xxxx.duckdns.org" --https

[FrancYescO]

As i didn't get how to use the builtin dns server (dns.coffee) i've added a server via another node lib 538bdfe let me know if looks good for you, the dns server will be started via --dnsserver and will resolve all queries to tch-exploit's ip