Suspected CL : https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/984900

Proposed fix: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/1001372

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/overlays/portage-stable/+/927d1e146806c51e3a725e24bd2e5028e97dd0e2

commit 927d1e146806c51e3a725e24bd2e5028e97dd0e2
Author: Manoj Gupta <manojgupta@google.com>
Date: Sat Apr 07 20:52:49 2018

certifi: Move EAPI to 5.

This is breaking chromiumos-sdk builder.
Root cause: Any package needed to build portage can't use EAPI 6.

BUG= chromium:830207 
TEST=chromiumos-sdk tryjob passes InitSDK stage.

Change-Id: I9947d83aecadd88747f1b8d43b83dc941b4cfc27
Reviewed-on: https://chromium-review.googlesource.com/1001372
Trybot-Ready: Manoj Gupta <manojgupta@chromium.org>
Reviewed-by: Luis Lozano <llozano@chromium.org>
Tested-by: Manoj Gupta <manojgupta@chromium.org>

[rename] https://crrev.com/927d1e146806c51e3a725e24bd2e5028e97dd0e2/dev-python/certifi/certifi-2017.4.17-r1.ebuild

Current build is going fine https://uberchromegw.corp.google.com/i/chromiumos/builders/chromiumos-sdk/builds/8686