Move actual test cases from the run-sample-tests.sh script to
the network samples directory that are supported by Docker based
testing. Each network sample directory that supports Docker testing,
will contain docker-test.sh script that is sourced by the runner
script. The docker-test.sh script will run the test as needed and
then return return value to the runner script.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>