Update example tests

Author: mdmintz

examples/basic_test.py

@@ -18,3 +18,4 @@ def test_basics(self):
         self.click('button:contains("Remove")')  # HTML innerText
         self.assert_text_not_visible("Backpack", "div.cart_item")
         self.js_click("a#logout_sidebar_link")
+        self.assert_element("div#login_button_container")

examples/my_first_test.py

@@ -26,6 +26,7 @@ def test_swag_labs(self):
         self.assert_exact_text("THANK YOU FOR YOUR ORDER", "h2")
         self.assert_element('img[alt="Pony Express"]')
         self.js_click("a#logout_sidebar_link")
+        self.assert_element("div#login_button_container")
 
         ####