refactor: remove unused imports.

common/djangoapps/student/helpers.py

@@ -21,7 +21,6 @@ from django.db import IntegrityError, transaction, ProgrammingError
 from django.urls import NoReverseMatch, reverse
 from django.utils.translation import ugettext as _
 from pytz import UTC
-from six import iteritems, text_type
 
 from common.djangoapps import third_party_auth
 from common.djangoapps.course_modes.models import CourseMode

common/djangoapps/student/management/tests/test_change_eligibility_deadline.py

@@ -6,7 +6,6 @@ import pytest
 
 from django.core.management import call_command
 from opaque_keys import InvalidKeyError
-from six import text_type
 from testfixtures import LogCapture
 
 from common.djangoapps.course_modes.tests.factories import CourseMode

lms/djangoapps/instructor/tests/test_api.py

@@ -23,7 +23,6 @@ from django.test import RequestFactory, TestCase
 from django.urls import reverse as django_reverse
 from django.utils.translation import ugettext as _
 from edx_when.api import get_dates_for_course, get_overrides_for_user, set_date_for_block
-from freezegun import freeze_time
 from opaque_keys.edx.keys import CourseKey
 from opaque_keys.edx.locator import UsageKey
 from pytz import UTC

openedx/features/discounts/tests/test_utils.py

@@ -4,7 +4,6 @@ Tests of the openedx.features.discounts.utils module.
 from unittest.mock import patch, Mock
 
 import ddt
-import six
 from django.contrib.auth.models import AnonymousUser
 from django.test import TestCase
 from django.utils.translation import override as override_lang

openedx/features/discounts/tests/test_views.py

@@ -2,7 +2,6 @@
 
 
 import jwt
-import six
 from django.test.client import Client
 from django.urls import reverse