Fixed flaky test

The retry fulfillment tests consistently fail on Travis. This change ensures we are waiting for the page to load before continuing the test.

ECOM-7141

ecommerce/extensions/dashboard/orders/tests.py

@@ -76,6 +76,9 @@ class OrderViewBrowserTestBase(LiveServerTestCase):
 
     def retry_fulfillment(self):
         """ Click the retry fulfillment button and wait for the AJAX call to finish. """
+        # Wait for the button to appear, otherwise calling tests may fail on Travis
+        WebDriverWait(self.selenium, 1.0).until(lambda d: d.find_element_by_css_selector(self.btn_selector))
+
         button = self.selenium.find_element_by_css_selector(self.btn_selector)
         self.assertEqual(unicode(self.order.number), button.get_attribute('data-order-number'))
         button.click()