Conpherence - unit tests for T7670

Summary: Ref T7670. Add a few unit tests to make sure deleting everyone works. Also change remaining processRequest to handleRequest while in there.

Test Plan: arc unit passed

Reviewers: chad, epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T7670

Differential Revision: https://secure.phabricator.com/D12179