Ability to support additional parameters?

[brian-learningpool]

I was wondering would you accept a PR to support an additional parameters object as part of the Strategy options?

I've been using the package to authenticate with OneLogin, and it works well, but in order to return custom attributes it requires the addition of a resource attribute to params.

[topbloc-beiswenger]

I also have a use case for this, trying to use additional parameters in the Okta API