Use unittest.mock instead of third party mock

Now that we no longer support py27, we can use the standard library
unittest.mock module instead of the third party mock lib.

Change-Id: I798eb2f2581cfca60c8c59fb35eb69f82cc963c4
Signed-off-by: Sean McGinnis <sean.mcginnis@gmail.com>

test-requirements.txt

@@ -5,7 +5,6 @@
 hacking>=1.1.0,<1.2.0 # Apache-2.0
 coverage>=3.6
 ddt>=0.7.0
-mock>=1.2
 python-subunit>=0.0.18
 selenium>=2.50.1 # Apache-2.0
 sphinx>=1.6.2 # BSD

trove_dashboard/content/database_backups/tests.py

@@ -12,13 +12,12 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from unittest import mock
+
 from django.urls import reverse
 from django.utils.translation import ugettext_lazy as _
-import mock
-
 from openstack_auth import policy
 from openstack_dashboard import api as dash_api
-
 from troveclient import common
 
 from trove_dashboard import api

trove_dashboard/content/database_clusters/tests.py

@@ -15,11 +15,9 @@
 #    under the License.
 
 import logging
+from unittest import mock
 
 from django.urls import reverse
-
-import mock
-
 from openstack_dashboard import api
 from troveclient import common
 

trove_dashboard/content/database_configurations/tests.py

@@ -13,7 +13,7 @@
 #    under the License.
 
 import logging
-import mock
+from unittest import mock
 
 import django
 from django.conf import settings

trove_dashboard/content/databases/logs/tests.py

@@ -13,17 +13,15 @@
 #    under the License.
 
 import logging
+from unittest import mock
 
 from django import http
 from django.urls import reverse
-
-import mock
+from swiftclient import client as swift_client
 
 from trove_dashboard import api
 from trove_dashboard.test import helpers as test
 
-from swiftclient import client as swift_client
-
 LINES = 50
 
 

trove_dashboard/content/databases/tests.py

@@ -14,14 +14,12 @@
 #    under the License.
 
 import logging
+import unittest
+from unittest import mock
 
 import django
 from django import http
 from django.urls import reverse
-import unittest
-
-import mock
-
 from horizon import exceptions
 from openstack_auth import policy
 from openstack_dashboard import api as dash_api