def url(item, url)
      data = read_file
      match_name(item)
      data[@@item]["url"] = url
      time(item)
      write_file(data)
    end
def url(item, url)
      data = read_file
      match_name(item)
      data[@@item]["url"] = url
      time(item)
      write_file(data)
    end
Set URL of existing item in Stocker's inventory
 @param item [String] item to update
 @param url [String] URL of item