prefer new unittest.mock everywhere

tests_app/tests/unit/cache/decorators/tests.py

@@ -1,6 +1,9 @@
 from django.core.cache import caches
 from django.test import TestCase
-from mock import Mock, patch
+try:
+    from unittest.mock import Mock, patch
+except ImportError:
+    from mock import Mock, patch
 from rest_framework import views
 from rest_framework.response import Response
 

tests_app/tests/unit/key_constructor/bits/tests.py

@@ -1,5 +1,7 @@
-from mock import Mock
-from mock import PropertyMock
+try:
+    from unittest.mock import Mock, PropertyMock
+except ImportError:
+    from mock import Mock, PropertyMock
 
 import django
 from django.test import TestCase

tests_app/tests/unit/key_constructor/constructor/tests.py

@@ -1,7 +1,10 @@
 from copy import deepcopy
 import hashlib
 import json
-from mock import Mock, patch
+try:
+    from unittest.mock import Mock, patch
+except ImportError:
+    from mock import Mock, patch
 
 from django.test import TestCase
 

tests_app/testutils.py

@@ -1,5 +1,8 @@
 import base64
-from mock import patch
+try:
+    from unittest.mock import patch
+except ImportError:
+    from mock import patch
 
 from rest_framework import HTTP_HEADER_ENCODING