dimagi/commcare-hq — pull request #4179 by kkrampa (2014-08-26 11:39:08+00:00)
Title: Added task to remove expired invitations

http://dimagi.uservoice.com/forums/194748-user-management/suggestions/4812770-delete-pending-invitations-send-an-expiry-notifica

I don't know when invitations should expire and also when we should ping invitee so for now this PR is incomplete.