[Redesign] Rebuild Roboto Slab
Summary: Ref T8755. Hunting down some display issues with the fonts on certain computers (Ubuntu, Windows, Chrome Mobile). Hopefully having the full font fallback tree will resolve the issues.
Test Plan: Review Phriction on my Mac, no distinguishable difference. Will test Ubuntu after it lands.
Reviewers: btrahan, epriestley
Reviewed By: epriestley
Subscribers: epriestley, Korvin
Maniphest Tasks: T8755
Differential Revision: https://secure.phabricator.com/D13552