Remove more python2 stuff

InvenTree/common/admin.py

@@ -1,6 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 from django.contrib import admin
 
 from import_export.admin import ImportExportModelAdmin

InvenTree/common/tasks.py

@@ -1,6 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 import logging
 from datetime import timedelta, datetime
 

InvenTree/common/test_notifications.py

@@ -1,6 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 from common.notifications import NotificationMethod, SingleNotificationMethod, BulkNotificationMethod, storage
 from plugin.models import NotificationUserSetting
 from part.test_part import BaseNotificationIntegrationTest

InvenTree/common/tests.py

@@ -1,5 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
+
 from http import HTTPStatus
 import json
 from datetime import timedelta