Added stestr for running test using pdb flag

The officially supported test runner for Tempest
is stestr.
config.py uses ostestr with pdb flag.
Hence, there is need to replace it.

Depends-On: https://review.opendev.org/#/c/698629/
Change-Id: Ie4a1fe87ed10e1ff306c52e4e72bea1825559602
Signed-off-by: Soniya Vyas <svyas@redhat.com>
1 file changed