Update an example test in the ReadMe

Author: mdmintz

README.md

@@ -114,9 +114,13 @@ class CoffeeCartTest(BaseCase):
     def test_coffee_cart(self):
         self.open("https://seleniumbase.io/coffee/")
         self.assert_title("Coffee Cart")
+        self.assert_element('button:contains("Total: $0.00")')
         self.click('div[data-sb="Cappuccino"]')
+        self.assert_exact_text("cart (1)", 'a[aria-label="Cart page"]')
         self.click('div[data-sb="Flat-White"]')
+        self.assert_exact_text("cart (2)", 'a[aria-label="Cart page"]')
         self.click('div[data-sb="Cafe-Latte"]')
+        self.assert_exact_text("cart (3)", 'a[aria-label="Cart page"]')
         self.click('a[aria-label="Cart page"]')
         self.assert_exact_text("Total: $53.00", "button.pay")
         self.click("button.pay")