Add role to users created by rally if required
Add role to users created by rally if required

It sets [openstack] keystone_default_role if NEW_USER_ROLE differs
from member.

Change-Id: Ib6be5cf22654e882ea110298cba421c1e87c78fd
Signed-off-by: Cédric Ollivier <d48310251a4a484d041bc5d09a9ac4d86d20f793@orange.com>

opnfv/functest,opnfv/functest