This commit adds SystemdWorker class to kolla_docker ansible module.
It is used to manage container state via systemd calls.

Change-Id: I20e65a6771ebeee462a3aaaabaa5f0596bdd0581
Signed-off-by: Ivan Halomi <i.halomi@partner.samsung.com>
Signed-off-by: Martin Hiner <m.hiner@partner.samsung.com>