Fix type mismatches in the course_groups migration.

Mixing byte and unicode strings causes migrations to fail.

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

@@ -24,7 +24,7 @@ class Migration(migrations.Migration):
             name='CourseCohort',
             fields=[
                 ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
-                ('assignment_type', models.CharField(default=b'manual', max_length=20, choices=[(b'random', b'Random'), (b'manual', b'Manual')])),
+                ('assignment_type', models.CharField(default='manual', max_length=20, choices=[('random', 'Random'), ('manual', 'Manual')])),
             ],
         ),
         migrations.CreateModel(
@@ -32,8 +32,8 @@ class Migration(migrations.Migration):
             fields=[
                 ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
                 ('is_cohorted', models.BooleanField(default=False)),
-                ('course_id', CourseKeyField(help_text=b'Which course are these settings associated with?', unique=True, max_length=255, db_index=True)),
-                ('_cohorted_discussions', models.TextField(null=True, db_column=b'cohorted_discussions', blank=True)),
+                ('course_id', CourseKeyField(help_text='Which course are these settings associated with?', unique=True, max_length=255, db_index=True)),
+                ('_cohorted_discussions', models.TextField(null=True, db_column='cohorted_discussions', blank=True)),
                 ('always_cohort_inline_discussions', models.BooleanField(default=True)),
             ],
         ),
@@ -41,18 +41,18 @@ class Migration(migrations.Migration):
             name='CourseUserGroup',
             fields=[
                 ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
-                ('name', models.CharField(help_text=b'What is the name of this group?  Must be unique within a course.', max_length=255)),
-                ('course_id', CourseKeyField(help_text=b'Which course is this group associated with?', max_length=255, db_index=True)),
-                ('group_type', models.CharField(max_length=20, choices=[(b'cohort', b'Cohort')])),
-                ('users', models.ManyToManyField(help_text=b'Who is in this group?', related_name='course_groups', to=settings.AUTH_USER_MODEL, db_index=True)),
+                ('name', models.CharField(help_text='What is the name of this group?  Must be unique within a course.', max_length=255)),
+                ('course_id', CourseKeyField(help_text='Which course is this group associated with?', max_length=255, db_index=True)),
+                ('group_type', models.CharField(max_length=20, choices=[('cohort', 'Cohort')])),
+                ('users', models.ManyToManyField(help_text='Who is in this group?', related_name='course_groups', to=settings.AUTH_USER_MODEL, db_index=True)),
             ],
         ),
         migrations.CreateModel(
             name='CourseUserGroupPartitionGroup',
             fields=[
                 ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
-                ('partition_id', models.IntegerField(help_text=b'contains the id of a cohorted partition in this course')),
-                ('group_id', models.IntegerField(help_text=b'contains the id of a specific group within the cohorted partition')),
+                ('partition_id', models.IntegerField(help_text='contains the id of a cohorted partition in this course')),
+                ('group_id', models.IntegerField(help_text='contains the id of a specific group within the cohorted partition')),
                 ('created_at', models.DateTimeField(auto_now_add=True)),
                 ('updated_at', models.DateTimeField(auto_now=True)),
                 ('course_user_group', models.OneToOneField(to='course_groups.CourseUserGroup', on_delete=models.CASCADE)),