Early preview of SSHAuthZ with OIDC support

This release supports authentication by an upstream OpenID Connect provider that can be used instead of relying upon request headers (set by, for example, Apache mod_shib). It also allows for user blacklisting to prevent certificates being issued under privileged accounts, such as root or "ubuntu".

v1.0.0

This version provides basic SSH certificate signing based on upstream authentication via HTTP headers (e.g. set by Apache mod_shib or mod_ldap).