Revisit isolation of Bearer token

[jcorry]

This seems error prone. Can you check the type of Authorization header as well? I know it will throw an unauthorized error if the length is not as expected which could be enough but just food for thought.

Maybe something like:

if len(bearerToken) == 2 && strings.Contains(bearerToken[0], "Bearer") {

Originally posted by @syntacticNaCl in #33