cleanup files that are created for swift functional tests

Currently this portion of code is also being run when running
tox to debug local tests. Which is very annoying since a developer
will end up with a bunch of uuid files. Rather than creating it
once per run, we can have a setup/teardown that is handled safely.

Change-Id: I49a0bb3d14f24c54da93458d1e3b9093a1120453
Merge "cleanup files that are created for swift functional tests"