Update name in a test and a ReadMe

Author: mdmintz

examples/visual_testing/ReadMe.md

@@ -95,10 +95,10 @@ class VisualLayoutTest(BaseCase):
     def test_python_home_layout_change_failure(self):
         self.open('https://python.org/')
         print('\nCreating baseline in "visual_baseline" folder.')
-        self.check_window(name="github_home", baseline=True)
+        self.check_window(name="python_home", baseline=True)
         # Remove the "Donate" button
         self.remove_element('a.donate-button')
-        self.check_window(name="github_home", level=3)
+        self.check_window(name="python_home", level=3)
 ```
 Here's the output of that:
 ```

examples/visual_testing/python_home_test.py

@@ -6,7 +6,7 @@ class VisualLayoutTest(BaseCase):
     def test_python_home_layout_change(self):
         self.open('https://python.org/')
         print('\nCreating baseline in "visual_baseline" folder.')
-        self.check_window(name="github_home", baseline=True)
+        self.check_window(name="python_home", baseline=True)
         # Remove the "Donate" button
         self.remove_element('a.donate-button')
-        self.check_window(name="github_home", level=0)
+        self.check_window(name="python_home", level=0)