Fix bug with monkeypatching

Author: imurchie

appium/webdriver/webdriver.py

@@ -45,9 +45,6 @@ def __init__(self, command_executor='http://127.0.0.1:4444/wd/hub',
         By.ANDROID_UIAUTOMATOR = MobileBy.ANDROID_UIAUTOMATOR
         By.ACCESSIBILITY_ID = MobileBy.ACCESSIBILITY_ID
 
-        # add methods to the WebElement class
-        WebElement.set_value = set_value
-
     @property
     def contexts(self):
         """