JWT config now takes an optional jwk_url parameter (which points to published JWK Set). This is useful for providers who rotate their JWK Set.
Optional jwk_url parameter is taken. The published JWK set under that URL should be in standard JWK format (tools.ietf.org/html/rfc7517#section-4.8).
If the response contains an Expires header, the JWK set is automatically refreshed.
