Update README.md

Author: bobjiangps

README.md

@@ -8,4 +8,4 @@ Auto test on remote mobile devices with openstf and appium / 自动化操作远
 require stf and adb environment.
 for stf environment, please refer to my blog post: https://www.byincd.com/bobjiang/article-0164/ .
 
-![Image text](https://www.byincd.com/media/upload/Bo/2019/02/28/stf_operation_page.png)
+![Image text](https://www.byincd.com/media/upload/Bo/2019/03/06/stf_screenshot_20190306.png)