Flow for UPE members to verify membership

[quasimik]

UPE members get unlimited credits. We need a flow that verifies that a user is a UPE member.

Possible flow:

1. Get a list of upe member emails from the postgres db
2. Have an input in the user profile page to associate a upe email with this user
3. Verify that email is on the list, then send verification email with link
4. Link in message associates the upe email with the user