Use keystoneclient fixtures in middleware tests

Convert the static tokens in auth_token middleware tests to use
keystoneclient fixture generators.

We still have fairly static entries for the values in the tokens because
of the way the tests work.

Change-Id: Id6ee0389e063d6476d9c33c3d955926655c8ca75
Example JSON files should be human-readable

Change-Id: I7b2869edcd7a6018f72a718d042231094ed40686
Merge "Example JSON files should be human-readable"
Merge "Use keystoneclient fixtures in middleware tests"