INCR-154 (#20485)

* INCR-154: Run python-modernize on openedx/core/djangoapps/dark_lang

* INCR-154: Grouping for absolute_import and unicode_literals at migrations

openedx/core/djangoapps/dark_lang/admin.py

@@ -2,6 +2,8 @@
 Admin site bindings for dark_lang
 """
 
+from __future__ import absolute_import
+
 from config_models.admin import ConfigurationModelAdmin
 from django.contrib import admin
 

openedx/core/djangoapps/dark_lang/middleware.py

@@ -7,6 +7,8 @@ Language setting page.
 This middleware must be placed before the LocaleMiddleware, but after
 the SessionMiddleware.
 """
+from __future__ import absolute_import
+
 from django.conf import settings
 from django.utils.translation import LANGUAGE_SESSION_KEY
 from django.utils.translation.trans_real import parse_accept_lang_header

openedx/core/djangoapps/dark_lang/migrations/0001_initial.py

@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-from __future__ import unicode_literals
+from __future__ import absolute_import, unicode_literals
 
 from django.db import migrations, models
 import django.db.models.deletion

openedx/core/djangoapps/dark_lang/migrations/0002_data__enable_on_install.py

@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-from __future__ import unicode_literals
+from __future__ import absolute_import, unicode_literals
 
 # Converted from the original South migration 0002_enable_on_install.py
 #

openedx/core/djangoapps/dark_lang/migrations/0003_auto_20180425_0359.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 # Generated by Django 1.11.12 on 2018-04-25 07:59
-from __future__ import unicode_literals
+from __future__ import absolute_import, unicode_literals
 
 from django.db import migrations, models
 

openedx/core/djangoapps/dark_lang/models.py

@@ -1,6 +1,8 @@
 """
 Models for the dark-launching languages
 """
+from __future__ import absolute_import
+
 from config_models.models import ConfigurationModel
 from django.db import models
 

openedx/core/djangoapps/dark_lang/tests.py

@@ -1,6 +1,8 @@
 """
 Tests of DarkLangMiddleware
 """
+from __future__ import absolute_import
+
 import unittest
 
 import ddt

openedx/core/djangoapps/dark_lang/urls.py

@@ -2,6 +2,8 @@
 Contains all the URLs for the Dark Language Support App
 """
 
+from __future__ import absolute_import
+
 from django.conf.urls import url
 
 from openedx.core.djangoapps.dark_lang import views

openedx/core/djangoapps/dark_lang/views.py

@@ -1,6 +1,8 @@
 """
 Views file for the Darklang Django App
 """
+from __future__ import absolute_import
+
 from django.contrib.auth.decorators import login_required
 from django.http import Http404
 from django.shortcuts import redirect