Add the token protobuf description and a few encoder/decoder methods.
Add a (currently failing) test for those codecs.
Verify the expiry timestamps on the various cookies and tokens.
Implement a method for the Authenticator to extract the authenticated
user from the token cookie.
Add a method for extracting scope data from the token cookie.
Python 3 compatible exceptions.
Write the signature for auth token requests to a reasonable place and
add some more information to the exceptions thrown during verification.
Reactivate the signature test.
Add and populate a request_authorization method.
Initial commit