subtests.docker_cli: add "docker restart" test

The test tries to restart docker and checks the results.

Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
index.rst: Fix the two spaces between bullet and text

Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
Merge pull request #42 from ldoktor/restart

subtests.docker_cli: add "docker restart" test