chromedp下载文件的方法，备忘一下。

 1     sect := `//a[@href="v/443.json"]`
 2     wd,_ := os.Getwd()
 3     fmt.Println(wd)
 4     return chromedp.Tasks{
 5         //chromedp.Navigate(url),
 6         chromedp.WaitVisible(sect),
 7         page.SetDownloadBehavior(page.SetDownloadBehaviorBehaviorAllow).WithDownloadPath(wd),
 8         chromedp.Click(sect, chromedp.NodeVisible),
 9         chromedp.Sleep(3 * time.Second),
10     }