Adapt create_tenant and create_user to keystone v3
Adapt create_tenant and create_user to keystone v3

JIRA: FUNCTEST-670

Change-Id: I5bb288be2dd5cee1776930ca94d1acad82f50160
Signed-off-by: jose.lausuch <a4ed9890ad7f6494ac84a749f29a4dc3449a1186@ericsson.com>

opnfv/functest,mywulin/functest,opnfv/functest,mywulin/functest