fixed warning about non-w3c conformity

tests/conftest.py

@@ -11,6 +11,7 @@ def chrome_options(chrome_options):
     chrome_options.add_argument('headless')
     chrome_options.add_argument('disable-gpu')
     chrome_options.add_argument('window-size=1200x600')
+    chrome_options.add_experimental_option('w3c', False)
     return chrome_options