Stability testing

[FossoresLP]

This project has been thrown together on an evening because I needed a DDNS client for NS1.
It has not been tested extensively and does not have any unit tests.
I have been using it for some time before publishing and had no issues besides some rate-limiting which is easy to work around be increasing the delay.
I'll do some more testing when I find the time and will update this issue accordingly.
When I deem this project stable enough I will tag the first release and add some binaries for Windows and Linux.

[FossoresLP]

There have been some issues with the NS1 API rejecting AAAA record updates with filters set to 'None' which seems to be done by default in the golang package provided by NS1. These have finally been fixed in the commits 11865c7 and 27d44f3