gyp

With this change, the tests should run fine on Python3 on Macs.
Python2 should work fine as well :).

Bug: gyp:36
Change-Id: I044746d44143b2e461feb4e5685d8bef3d6bbd19
Reviewed-on: https://chromium-review.googlesource.com/c/1361812


Reviewed-by: Mark Mentovai <mark@chromium.org>