Add support for octoDNS (multi-provider)

[josvo]

This PR adds an API for octoDNS (see https://github.com/github/octodns) so that you are able to push your TXT record to multiple providers. It is basically just a wrapper for other APIs so make sure the APIs of your provider works and you have exported (or saved) their credentials before calling this API.

[Neilpang]

please read this guide first: https://github.com/acmesh-official/acme.sh/wiki/DNS-API-Dev-Guide

[josvo]

please read this guide first: https://github.com/acmesh-official/acme.sh/wiki/DNS-API-Dev-Guide

@Neilpang Thanks for you commen: 2. The script file is named: dns_octodns.sh 3. file is placed in acme.sh/dnsapi 4. The file shebang is sh 5. the add and rm functions are in the script 9. I'll update the wiki as soon as this get's merged - doesn't make much sense as long as it is not merged. Style guides: script is checked with shellcheck.net

If you have a hint were I should change something, please provide some more information and I'll be happy to work on it until it fullfills your standards.

[josvo]

Hello @Neilpang Is there anything I can do for this PR? Please let me know. Thanks for your efforts!

[Neilpang]

I need more time to think about it.

[josvo]

@Neilpang: I this functionality not needed, not wanted or implemented otherwise?

[Neilpang]

sorry, it was closed by accident.

[josvo]

@Neilpang No problem :smiley: Please let me know if I can do something here - we are already using this in production for quite some time.