We add the necessary Paste filters for Keystone middleware and context
usage inside of Craton so that operators can use Keystone for Identity
and Access Management of Craton.
We also clean up our Keystone Context Middleware to access the
attributes that the keystonemiddleware library set on a request object
so we can determine if the token sent has been validated and what the
roles the user own.
Due to the effort exerted to get this working, this also adds
documentation around how to set up Craton to use Keystone for identity
and adds a tiny script in the `tools/` directory so that one can explore
the API interactively with keystone authentication.
Change-Id: Ida86881f1e6097b1a1f6dec912f094c53c2f4cc2
2407803170