GitHub provider whitelist with username?

[Poeschl]

Would it be possible to fallback to the username in case of the GitHub OAuth? With that users could als be whitelisted and filtered by rules.

I understand that its a custom setting just for GitHub but maybe it can be also a setting for the oauth provider.
For example --providers.generic-oauth.user-field=login to specify the login attribute of the User Url endpoint.

[thomseddon]

I think #159 would work for you?

Please re-open if not