Include tacker.conf.sample due to issues with tox, etc

Include tacker.conf.sample due to issues with tox, etc

JIRA: MODELS-23
Change from OSC to specific clients (e.g. neutron) due to
issues with newton version of the OSC.
Add apt-utils install due to not in default Xenial container.
Fix branch selection for OSC and other clients.
Comment out tox section (throwing exceptions for some reason).
Use tacker.conf.sample included in the repo.
Fix test for VNF active (tacker vnf-show).
Add loop for server up test.
Add OpenStack branch as option.

Change-Id: Id85b433e94df57c7b68f7feec2ce9cf6b2b238e0
Signed-off-by: Bryan Sullivan <bryan.sullivan@att.com>