Brings the legacy functional test jobs into the project repository,
rewritten for zuul3. The base functional test class has been refactored
to use clouds.yaml, and the functional-swift test has been refactored
to use keystoneauth1. The devstack hooks have been removed as they
are not necessary with zuul3.
Needed-By: I2a5ff2ee29e2fb8a730406f9f0e6a450b96c85b8
Needed-By: I96600383c072e6d2926f5ff5b6a51057e53d35fd
Change-Id: Iecea4375d1c4832b020b542ca4188b02444325ca