SDDNS

SDDNS is middleware for CoreDNS

1. Clone CoreDNS
2. Add SDDNS to imports in core/coredns.go "github.com/wil3/sddns"

3.In core/dnsserver/directives.go add sddns to directives array.

4. Add SDDNS to CoreDNS's configuration file, Corefile