Not compliant with new authentication standards in ACMEv2 (POST-as-GET)

[mtunstill]

Whilst experimenting with this project; I've hit a brick wall where v2 support will be totally broken for most actions when talking to ACME server (especially via Let's Encrypt's Boulder).

Unauthenticated GETs are now unsupported from ACME v2 STAGING and fully gone in v2 PRODUCTION by November 2020.

https://mailarchive.ietf.org/arch/msg/acme/sotffSQ0OWV-qQJodLwWYWcEVKI
https://community.letsencrypt.org/t/acme-v2-scheduled-deprecation-of-unauthenticated-resource-gets/74380

[larryboymi]

Thanks for submitting this! Will check it out