Cloned from launchpad blueprint https://blueprints.launchpad.net/keystone/+spec/no-tokens-in-db.

Description:

Move toward a configuration where:
1.  Tokens only live for a short period of time based on the acceptable delay for propegating revocation events.
2.  Remove tokens from the backend store.

Tokens will not live for the duration of the entire workflow.  Instead, services in the workflow will fetch tokens via delegation agreements.  This will require a significant effort into implementing proper delegation  policies and using trusts/oauth.  

Specification URL (additional information):

None