Mail attribute for Slack

[Peter Schober]

* Michael Brogan <mbrogan at uw.edu> [2018-01-12 18:56]:
> At the UW we've had a few Slack instances running with SSO and our
> IdP. Recently, for a new instance, we were told that the
> requirements have changed and that the IdP must release the mail
> attribute and that it must be asserted with a friendly name of
> "User.Email".

Even looking at friendlyName is a bug on their side, IMO.
-peter