Mock SSO locally

[mxmeinhold]

It would be really nice if SSO could be easily mocked to allow for local testing without needing credentials, similarly to how LDAP was mocked in #216, though at first glance I suspect SSO will be more involved.

[gidoBOSSftw5731]

I'd be down to make/configure an SSO mock thing with like some standard test accounts if that doesn't already exist