docker-compose: added `restart` policy
docker-compose: added `restart` policy

zultron/docker-provisioning,korczis/docker-squid-rubygems-proxy,boliu83/docker-squid,Optibus/docker-squid,opendoor-labs/docker-squid-s3,maqsoodumt/docker-squid,korczis/docker-squid-rubygems-proxy,linearregression/docker-squid-s3,sameersbn/docker-squid