added docker service to travis.yml
added docker service to travis.yml

Signed-off-by: Patrick Münch <3d5fc16192473046cf080abca113f9b6fc016432@gmail.com>

hardening-io/chef-ssh-hardening,hardening-io/chef-ssh-hardening,dev-sec/chef-ssh-hardening,dev-sec/chef-ssh-hardening