Update screenshot_test.py

Author: JE-Chen

test/unit_test/screen/screenshot_test.py

@@ -1,4 +1,5 @@
 import subprocess
+import time
 
 from je_auto_control import screenshot
 
@@ -9,6 +10,8 @@
 
 subprocess.Popen("notepad.exe", stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, shell=True)
 
+time.sleep(10)
+
 # screenshot and save
 image = screenshot("test.png")
 assert (image is not None)