Added unique constraint on email
ECOM-7085
(cherry picked from commit d141eb15)
No-op a migration that needs to be more clever
(cherry picked from commit 1e6a74e7)
model_name can be non-None, and model is still None
(cherry picked from commit 52ca02fd)
An idempotent migration to add an email uniqueness constraint
(cherry picked from commit 169414b7)
Make this no-op migration be a true no-op.
(cherry picked from commit 04557bbf)
A new django app for unicorn migrations
(cherry picked from commit 98b250b6)
