Fix unittest mock imports that triggered the linter

guardian/testapp/tests/test_conf.py

@@ -1,6 +1,6 @@
 from django.core.exceptions import ImproperlyConfigured
 from django.test import TestCase
-import mock
+from unittest import mock
 from guardian.conf import settings as guardian_settings
 from guardian.ctypes import get_content_type
 

guardian/testapp/tests/test_decorators.py

@@ -14,7 +14,7 @@
 
 from guardian.compat import get_user_model_path
 from guardian.compat import get_user_permission_full_codename
-import mock
+from unittest import mock
 from guardian.decorators import permission_required, permission_required_or_403, permission_required_or_404
 from guardian.exceptions import GuardianError
 from guardian.exceptions import WrongAppError

guardian/testapp/tests/test_management.py

@@ -5,7 +5,7 @@
 from django.contrib.sessions.models import Session
 from django.test import TestCase, override_settings
 
-import mock
+from unittest import mock
 from guardian.management import create_anonymous_user
 from guardian.utils import get_anonymous_user
 

guardian/testapp/tests/test_managers.py

@@ -1,6 +1,6 @@
 import warnings
 
-import mock
+from unittest import mock
 from django.test import TestCase
 from guardian.managers import UserObjectPermissionManager
 from guardian.managers import GroupObjectPermissionManager

guardian/testapp/tests/test_mixins.py

@@ -9,7 +9,7 @@
 from django.views.generic import ListView
 
 from guardian.shortcuts import assign_perm
-import mock
+from unittest import mock
 from guardian.mixins import LoginRequiredMixin
 from guardian.mixins import PermissionRequiredMixin
 from guardian.mixins import PermissionListMixin

guardian/testapp/tests/test_other.py

@@ -1,4 +1,4 @@
-import mock
+from unittest import mock
 import unittest
 
 from django.contrib.auth import get_user_model