code: func deleteReadingByIdHandler(w http.ResponseWriter, r *http.Request) {
  	defer r.Body.Close()
  
  	vars := mux.Vars(r)
  	id := vars["id"]
  
  	switch r.Method {
  	case http.MethodDelete:
  		err := deleteReadingById(id)
  		if err != nil {
  			switch err := err.(type) {
  			case *errors.ErrDbNotFound:
  				http.Error(w, err.Error(), http.StatusNotFound)
  				return
  			default: //return an error on everything else.
  				http.Error(w, err.Error(), http.StatusInternalServerError)
  				return
  			}
  		}
  
  		w.Header().Set("Content-Type", "application/json")
  		w.WriteHeader(http.StatusOK)
  		w.Write([]byte("true"))
  	}
  }
docs: // Delete a reading by its id
  // api/v1/reading/id/{id}