Enable OIDC refresh middleware to support federated logout.
Enable OIDC refresh middleware to support federated logout.

* Add the verification client urls to OIDC_EXEMPT_URLS.

johngian/mozillians,johngian/mozillians,akatsoulas/mozillians,mozilla/mozillians,mozilla/mozillians,akatsoulas/mozillians,mozilla/mozillians,akatsoulas/mozillians,johngian/mozillians,akatsoulas/mozillians,johngian/mozillians,mozilla/mozillians