Modified SFC test suite for creating flows in sff's and classifiers

Modified SFC test suite for creating flows in sff's and classifiers

Iptables must be flushed and one interface must be configured in the
classifiers before configuring classifiers

Add route in ODL system to reach the docker network in tools env.

Adjust SFC json configuration to the one used in SFC demo sfc-103
and remove dependance on static IPs in the config files.

Remove lithium configuration folder in variables directory and
remove condition linked to the release used at the time of
choosing configuration folder inside robot suites files.

Add new library to wrap the use of Docker containers within the
Robot framework tests. Library name: DockerSfc.robot
And another library for auxiliary functions used within the Sfc
tests. Libary name: SfcUtils.py

Change-Id: I9d6afbe2cdbcc3889a0267893a8003f9e074e175
Signed-off-by: ematejo <jose.angel.mateos.ramos@ericsson.com>