subtests.docker_cli: Add test run_cidfile

Fixes: https://github.com/autotest/autotest-docker/issues/264

This test is focussed on correct handling of `docker run --cidfile`

Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
Don't worry, `containers` is local list of `dkrcmd`s. For cleanup purposes I store the container name in `sub_stuff` long before `dkrcmd` is executed.