* Add DDNS connectivity check when validating zone connections.
* Add unit tests for DDNS connectivity test.
* Update functional tests for DDNS connectivity test.
* Update create zone documentation with DDNS connectivity information.
* Updates based on feedback (pauljamescleary).
* Convert TSIG key algoritm from default HMAC-MD5 to HMAC-SHA512.
* Updates based on feedback.
* open up NS access to all
* func tests for open up NS access
* actually use the approved name servers list
* testing for approved NS list
* IT tests for ns access changes
* share NS functions
* NS cleanup
* add spec for NS zone validations
