Stash Auth0 public key in AWS secret.

[Bento007]

The /.well-known/jwks.json provided by Auth0 has a rate limit that prevents services from verifying JWTs. To avoid hitting this rate limit we should store the key provided by that endpoint in AWS secret store.

DoD

• Store the key found at https://humancellatlas.auth0.com/.well-known/jwks.json in an AWS secret.
• Cache the secret in AWS Lambdas.
• If the secret fails to verify a JWT, refresh the secret from Auth0 to Secret Store and try again.