Add tempest_scenario and tempest_slow in smoke-cntt
Add tempest_scenario and tempest_slow in smoke-cntt

The testcases related to ipv6 are currenty not executed because they
cannot be covered by our SUTs.

Close cntt-n/CNTT#696

Change-Id: Ic0ca3818011bede965702e778f37752059c86173
Signed-off-by: Cédric Ollivier <d48310251a4a484d041bc5d09a9ac4d86d20f793@orange.com>

opnfv/functest,opnfv/functest