code: func del(db keyval.ProtoBroker, data string) {
  	c := &phonebook.Contact{Name: data}
  
  	key := phonebook.EtcdContactPath(c)
  
  	existed, err := db.Delete(key)
  	if err != nil {
  		log.Fatal(err)
  	} else if !existed {
  		fmt.Println("Not existed")
  		return
  	}
  
  	fmt.Println("Deleted:", key)
  }
docs: // del deletes single entry