Require canonical numbers in routes

Summary:
D03646 works, I don't want it to work.
Theoretically, it can cause us some troubles if we use this string in JS number context where 030 is 24.

Test Plan: D03646, D3646

Reviewers: epriestley, edward

Reviewed By: edward

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D3646