Fix an error of tox -ecover
Fix an error of tox -ecover

When we used tox -ecover, an error occurred about
'coverage-package-name'. This patch fixes it with changing the argument
of setup.py.

Change-Id: I419683f2474ce37a1df82b611c8637c0c76c9df7

cneill/tempest-lib,varunarya10/tempest-lib,sorenh/tempest-lib,JioCloud/tempest-lib