Roll "vpython" to: 00f5394a90dfa98e53e191d5a6b543bce70c295f

BUG=None
TEST=None
TBR=iannucci@chromium.org

Change-Id: Ia8b5d29a916fb186bdbff9dac4d63526c5f3e2ac
Reviewed-on: https://chromium-review.googlesource.com/505930Reviewed-by: Daniel Jacques <dnj@chromium.org>
Commit-Queue: Daniel Jacques <dnj@chromium.org>