* Add AUTODNSSEC, implement for DNSimple
There are two models for DNSSEC in DNS management: either dnscontrol
manages all the DNSSEC records and has to be invoked regularly for
re-signing, or the provider manages DNSSEC automatically and dnscontrol
is not involved beyond saying "yeah, do that".
This implements the latter, as a model, and for one provider.
Potentially we could tune/configure options for DNSSEC such as
algorithm, but DNSimple don't expose that API so I haven't implemented
it.
This minimal model should be something which maps into other providers
cleanly.
* Fix missing CanAutoDNSSEC on provider
* Validation fix for master broken
This is broken in master and causing Travis in my branch to fail. The
validation tool runs with `gofmt -s` to require "simplify", and so
rejects an ignored second bound variable to range iteration.
* Correct wire in the AUTODNSSEC validation step
