code: func FnListContainers(client *docker.Client) (containers []docker.APIContainers, err error) {
  	hostContainers, err := client.ListContainers(docker.ListContainersOptions{
  		All: true,
  	})
  	if err != nil {
  		containers = nil
  		return
  	}
  	for _, container := range hostContainers {
  		if strings.HasPrefix(container.Image, "gofn/") {
  			containers = append(containers, container)
  		}
  	}
  	return
  }
docs: // FnListContainers lists all the containers created by the gofn.
  // It returns the APIContainers from the API, but have to be formatted for pretty printing