v3.0.0 acme_client (PJAC)

Changes:

• acme4j updated to version 2.2
• ACME protocol updated to version 2 (wildcard certificates are supported now)

Breaking changes:

• Commands: renew-certificate, update-agreement and authorize-domains are removed.
• New command order-certificate is added.

See the wiki to get information about new certificate order flow:
https://github.com/porunov/acme_client/wiki