* Improvements to DNS validator to include IPv6 (#1312)
* improvements to DNS validator to include IPv6
* fixed the DNS validators
* updated per suggestions
* Update const.py
* Update dns.py
* Update validate.py
* Update validate.py
* Update dns.py
* Update test_validate.py
* Update validate.py
* Cleanup
* Don't set default DNS server as default
* Remove update local resolver
* Fix lint