code: func (a *API) robots(res http.ResponseWriter, req *http.Request) {
  	jsonRobots := []*gobot.JSONRobot{}
  	a.master.Robots().Each(func(r *gobot.Robot) {
  		jsonRobots = append(jsonRobots, gobot.NewJSONRobot(r))
  	})
  	a.writeJSON(map[string]interface{}{"robots": jsonRobots}, res)
  }
docs: // robots returns route handler.
  // Writes JSON with robots representation