Update build to use pbr.

Change-Id: If27004df4c756ebc0b00784cb0445ab46ea43d97
Upgrade testing to use testr.

Change-Id: Ib0e73c125c908898735e60e5b435468bc2b08316
Re-work test_cli to use testscenarios.

The cli tests were already organized in a manner that lets testscenarios
do what it does. Reformat the code a little bit to be a single test plus
a list of declarative combinations of scenarios and let testscenarios
do the work of turning that into a set of test cases.

Change-Id: I4e10d9eaeb313c724f0012babac465e37be4fa3d
Merge "Update build to use pbr."
Merge "Upgrade testing to use testr."
Merge "Re-work test_cli to use testscenarios."