1. Certificate issuance:
- issue wildcard certificates
- issue certificates for more than one domain (hostname in subject DN CN attribute and SAN DNS.01 field).
This was tested with ACME clients certbot 0.37.0 and PJAC 3.0.1, but there should be a unit/system test as well.
2. Response HTTP status codes and ACME problem types (tbd. talk to maggie).