HTTPClient() tenant_id and tenant_name parameters weren't properly
deprecated since they were only mentioned in the docstring. Proper
deprecation requires use of warnings/debtcollector and documentation.
Also fixed a bunch of places in the tests where tenant_id and
tenant_name were still being used despite being deprecated.
bp deprecations
Change-Id: I9c4f596b8ff10aede6c417886638a942cb18044c