code: func hapiLogoutSubmit(w http.ResponseWriter, r *http.Request) {
  	cookie, err := r.Cookie("id")
  	if err != nil {
  		writeError(w, err)
  		return
  	}
  	uid := cookie.Value
  	if uid == "null" {
  		http.Error(w, "id was null", http.StatusBadRequest)
  		return
  	}
  	q := `DELETE FROM sessions WHERE userid=$1`
  	if _, err = db.Exec(q, uid); err != nil {
  		writeError(w, err)
  		return
  	}
  	w.WriteHeader(http.StatusOK)
  }
docs: // hapiLogoutSubmit processes a logout request deleting the session from
  // the server.