Remove unique constraint from initial field

src/membership/migrations/0009_membership_referral_code.py

@@ -21,7 +21,7 @@ class Migration(migrations.Migration):
         migrations.AddField(
             model_name='membership',
             name='referral_code',
-            field=models.UUIDField(blank=True, null=True, unique=True, default=uuid.uuid4, editable=False),
+            field=models.UUIDField(blank=True, null=True, default=uuid.uuid4, editable=False),
         ),
         migrations.RunPython(create_uuid),
         migrations.AlterField(