Add job to run swift functional tests.

Run swift functional tests against a devstack vm.

Change-Id: I26a33de6bd413cbc73f65a99c03c091f8b7799c9
Reviewed-on: https://review.openstack.org/32125
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Approved: James E. Blair <corvus@inaugust.com>
Reviewed-by: James E. Blair <corvus@inaugust.com>
Tested-by: Jenkins