A refresh request must fail if it asks for scopes that were not
originally granted when the refresh token was obtained.
This Commit:
* changes repo to store scopes with tokens
* changes repo interface signatures so that scopes can be stored and
verified
* updates dependent code to pass along scopes
This enables us to control the length of the bytes that will be bcrypted,
by default it's 64.
Also changed the token's stored form from string('text') to []byte('bytea')
and added some test cases for different types of invalid tokens.