Added Arcanist configuration.
Added Arcanist configuration.

Test Plan: No test plan for this.

Reviewers: teppo

Reviewed By: teppo

Differential Revision: http://wunder.sytes.net:81/D1

simman/Taskboard,tarlepp/Taskboard,tarlepp/Taskboard,simman/Taskboard,tarlepp/Taskboard,simman/Taskboard