As tempest_lib is deprecated. The code has been
re-integrated in tempest under the tempest.lib
namespace, no modifies could be done to tempest_lib.
We should use tempest.lib instead of tempest_lib
to make the tests passed when we remove support
for --endpoint-type.
Change-Id: I864aa967fe6895b8f193a6ec7506dc743b0b3392