Run Maniphest Conduit writes through new editor

Summary: Ref T2217. Swap the editors for the Conduit writes.

Test Plan: Made a bazillion Conduit calls, saw tasks updated appropriately.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2217

Differential Revision: https://secure.phabricator.com/D7082