when importing/syncing with airtable, there needs to be a way to handle duplicate email addresses in the users table

[sdklos]

we are finding users in airtable and matching them up with progbot by email address. if there are duplicates of the email address in airtable you end up in a kind of infinite back and forth (haven't quite figured out why yet) where the user gets updated over and over again. there needs to be a way to manage a situation like this - either by not allowing duplicates in airtable (not sure that's possible) or having some kind of flag on the progbot side to notify admins of this situation, and to only pay attention to (for example) the most recently updated one in airtable and ignore the other one.