This commit adds the infrastructure for multi user testing. It also adds
a small set of test cases that exercises RBAC policy for secret and
container reads.
Six users with four roles and two projects are added.
In Project A: admin_a, creator_a, observer_a, auditor_a
In Project B: admin_b, observer_b
Get Secrets and Get Containers are tested for each user.
Implements: blueprint add-run-as-for-functional-tests
Relates-to: blueprint multi-user-functional-tests
Change-Id: I65c820440c014301cfce90d360440d3e12e7ffba