Convention over configuration

Jira: [VAL-83]

bluva.py is taking varibles.yaml and writing updated version to
varibles_updated.yaml

varibles_updated.yaml is passed to robot framework.
OperatingSystem.Get Environment is better than $HOME.
Each container automatically removed
Each test suite has a debug.log by default

Signed-off-by: Naga Sugguna <ns156u@att.com>
Change-Id: Iae95d1ee12c8c5e44949be3faf5b0fc9fc40266e