Move dark_lang and lang_pref apps to openedx/core

lms/djangoapps/courseware/tests/test_i18n.py

@@ -1,7 +1,9 @@
 """
 Tests i18n in courseware
 """
+
 import re
+
 from django.conf import settings
 from django.contrib.auth.models import User
 from django.core.urlresolvers import reverse
@@ -9,10 +11,10 @@ from django.test import TestCase
 from django.test.client import Client
 from django.utils import translation
 from nose.plugins.attrib import attr
-from openedx.core.djangoapps.user_api.preferences.api import set_user_preference
 
-from dark_lang.models import DarkLangConfig
-from lang_pref import LANGUAGE_KEY
+from openedx.core.djangoapps.dark_lang.models import DarkLangConfig
+from openedx.core.djangoapps.lang_pref import LANGUAGE_KEY
+from openedx.core.djangoapps.user_api.preferences.api import set_user_preference
 from student.tests.factories import UserFactory