mixpanel.people.increment should create the property if it doesn't exist

[chrysb]

If I have mixpanel.people.increment('Total Referrals', 1) and "Total Referrals" doesn't exist, it doesn't create the property. It would be super helpful if it did.

I could easily add Total Referrals for new users, but adding it for existing users would be tough, because I can't easily check if it already exists on a given user before creating it, as migrating existing users might overwrite any subsequent values that have been incremented.

Can we add this feature?