dockertest: Adds after traceback new line char to improve readability.

Signed-off-by: Jiří Župka <jzupka@redhat.com>
dockertest: Adds get_as_list function to config.

Signed-off-by: Jiří Župka <jzupka@redhat.com>
Merge branch 'config_fix_traceback' of https://github.com/jzupka/autotest-docker
dockertest.config: get_as_list fix + unittest

*  ``sep`` parameter never referenced
*  Strip entire value also before splitting
*  String-convert all value
*  Added unittest

Signed-off-by: Chris Evich <cevich@redhat.com>