Added
* New method to determine the actual zone name for a given FQDN. Historically it was an extraction
of the second-level domain given well-known TLDs (eg., `domain.net` for `www.domain.net`) using
`tldextract`, and usage of `--delegated` option to enforce a specific zone name that is useful for
third-level domains hosted on a specific zone (eg., sub-zone `sub.domain.net` delegated from zone
`domain.net`).
It is now possible to use the `--resolve-zone-name` flag on Lexicon client to trigger an actual
resolution of the zone name from a given FQDN using live DNS servers by leveraging `dnspython`
utilities. Most of the time this makes `--delegated` useless, since Lexicon will be able to guess
the correct zone name.