Add a custom lint name hook to Phabricator

Summary: Allow Conduit method so they stop raising lint warnings. See D874.

Test Plan: Ran "arc lint" on conduit files and was no longer given frivolous
warnings.

Reviewers: nh, jungejason, tuomaspelkonen, aran

Reviewed By: nh

CC: aran, nh, epriestley

Differential Revision: 875