Add missing rzone.Err checks

Fix CNAME chain following (#20)

Upgrade dependencies

Bump github.com/miekg/dns from 1.1.22 to 1.1.25

Bumps [github.com/miekg/dns](https://github.com/miekg/dns) from 1.1.22 to 1.1.25.
- [Release notes](https://github.com/miekg/dns/releases)
- [Changelog](https://github.com/miekg/dns/blob/master/Makefile.release)
- [Commits](miekg/dns@v1.1.22...v1.1.25)

---
updated-dependencies:
- dependency-name: github.com/miekg/dns
  dependency-type: direct:production
...

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