Fix flaky bok choy tests.

TNL-2667

common/test/acceptance/pages/studio/users.py

@@ -254,6 +254,7 @@ class UserWrapper(PageObject):
         self.wait_for_element_visibility('.prompt', 'Prompt is visible')
         self.wait_for_element_visibility('.prompt .action-primary', 'Confirmation button is visible')
         self.q(css='.prompt .action-primary').click()
+        self.wait_for_element_absence('.page-prompt .is-shown', 'Confirmation prompt is hidden')
         wait_for_ajax_or_reload(self.browser)
 
     @property

common/test/acceptance/tests/studio/test_studio_course_team.py

 """
 Acceptance tests for course in studio
 """
-from flaky import flaky
 from nose.plugins.attrib import attr
 
 from .base_studio_test import StudioCourseTest
@@ -11,7 +10,6 @@ from ...pages.studio.users import CourseTeamPage
 from ...pages.studio.index import DashboardPage
 
 
-@flaky  # TODO fix this, see TNL-2667
 @attr('shard_2')
 class CourseTeamPageTest(StudioCourseTest):
     """ As a course author, I want to be able to add others to my team """
@@ -75,9 +73,15 @@ class CourseTeamPageTest(StudioCourseTest):
     def _assert_user_present(self, user, present=True):
         """ Checks if specified user present on Course Team page """
         if present:
-            self.assertIn(user.get('username'), self.page.usernames)
+            self.page.wait_for(
+                lambda: user.get('username') in self.page.usernames,
+                description="Wait for user to be present"
+            )
         else:
-            self.assertNotIn(user.get('username'), self.page.usernames)
+            self.page.wait_for(
+                lambda: user.get('username') not in self.page.usernames,
+                description="Wait for user to be absent"
+            )
 
     def _should_see_dialog(self, dialog_type, dialog_message):
         """ Asserts dialog with specified message is shown """
@@ -152,7 +156,6 @@ class CourseTeamPageTest(StudioCourseTest):
 
         self._assert_can_not_manage_users()
 
-    @flaky  # TNL-3515
     def test_admins_can_delete_other_users(self):
         """
         Scenario: Admins can delete other users