Groups claim isn't returned in the ID token for OKTA

[taha-au]

We use Okta as our IdP and for OIDC to work with Okta, a further call needs to be made to the /userinfo endpoint to get the groups info since Okta doesn't encode that claim into the token.

[taha-au]

This issue is addressed in #39. Please let me know if you need anything else before this can be shipped.

[moroienius]

i've confirm same issue when using Okta.After applying fix from #39 i got groups fine

[tjuerge]

Merged #39 - thanks @taha-au

[taha-au]

@tjuerge sorry about not following up to address the comments. thanks for seeing this through!