pglister: bug: Can't add moderators (and create lists)

Hello,

I'm still in the process of writing an install script for pglister. I'm at the point where auth is working and I'm testing lists.

In the interface (in /admin/lists/list/1/change/), I cannot create a list because the "Moderators" field is always empty, and django won't let me create a list without moderators.
As a workaround, I removed the necessity to have a moderator to test if I can add subscribers after list creation, but I still cannot add any after list creation. See migration attached (I added both patch and migration, I'm not sure how you're supposed to properly edit django apps)
I'm a bit confused because django has "staff" and "superuser", but none of that is the same as moderators, and I can't seem to find the way to promote a user into one.

Am I missing something?

Cheers,
-- 
Célestin Matte