Fixes #232: support getting public key signatures from x5c, x5u, jku, jwk claims along with Auth0's own scheme.
Fixes #232: support getting public key signatures from x5c, x5u, jku,
jwk claims along with Auth0's own scheme.

simo5/jsonwebtoken.github.io,nov/jsonwebtoken.github.io,simo5/jsonwebtoken.github.io,nov/jsonwebtoken.github.io