Duo integration type for IdP Duo integration

[Jim Fox]

> 
> Agreed, Jim, that it's obvious. Our fear was that, if we didn't go with the Shibboleth integration type, something else might break later even if it works now.
>
> But if Duo told you all to use the Web SDK integration type for your IdP, it doesn't sound like that's likely to happen. At least I think that's what you're saying Duo told you all to do last spring.
>

Yes, our MFA flow uses the Duo iframe and makes API calls.  We have to use 
a shibboleth integration client for the iframe and an SDK client for the 
API.  Duo is aware of this and recognizes it as not uncommon usage.

Jim