Fixup! Make string quoting consistent (prefer single quotes)

lms/djangoapps/django_comment_client/management/commands/create_roles_for_existing.py

@@ -16,7 +16,7 @@ class Command(BaseCommand):
     help = 'Seed default permisssions and roles.'
 
     def handle(self, *args, **options):
-        print("Updated roles for ", end=' ')
+        print('Updated roles for ', end=' ')
         for i, enrollment in enumerate(CourseEnrollment.objects.filter(is_active=1), start=1):
             assign_default_role_on_enrollment(None, enrollment)
             if i % 1000 == 0:

lms/djangoapps/django_comment_client/management/commands/get_discussion_link.py

@@ -5,7 +5,7 @@ from courseware.courses import get_course
 
 
 class Command(BaseCommand):
-    help = "Write a discussion link for a given course on standard output."
+    help = 'Write a discussion link for a given course on standard output.'
 
     def add_arguments(self, parser):
         parser.add_argument('course_id',
@@ -18,7 +18,7 @@ class Command(BaseCommand):
 
         course = get_course(course_key)
         if not course:
-            raise CommandError("Invalid course id: {}".format(course_id))
+            raise CommandError('Invalid course id: {}'.format(course_id))
 
         if course.discussion_link:
             self.stdout.write(course.discussion_link)