Add support for failure redirect

[ahmednasir91]

PassportJS has a failureRedirect route which can be provided by client to show a custom error page.

The case i've is if you hit authorization-code/callback?error=access_denied if will just show Unauthorized and not an easy way to override this error page or show a page.

I propose, provided the clients ability to provide failureRedirect for passport similar to successReturnToOrRedirect.

[ahmednasir91]

Let me know your thoughts about this change
ahmednasir91@aeb7d37

I can create a pull request, if this looks good.

[robertjd]

Thanks @ahmednasir91 , this looks good and I'd love to see a PR. With that PR can you also document this option in the README? I'll also need to send you over to our CLA before we can merge: https://developer.okta.com/cla/

Thanks again!

[ahmednasir91]

@robertjd created a pull request #118