[Checkins] [zopefoundation/Zope] de7f11: Update to ExtensionClass 4.2.1.

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/zopefoundation/Zope
  Commit: de7f115e5def8f6fe823af9e3d2c06741bb2b0f0
      https://github.com/zopefoundation/Zope/commit/de7f115e5def8f6fe823af9e3d2c06741bb2b0f0
  Author: Hanno Schlichting <hanno at hannosch.eu>
  Date:   2017-02-02 (Thu, 02 Feb 2017)

  Changed paths:
    M CHANGES.rst
    M requirements-full.txt
    M versions-prod.cfg

  Log Message:
  -----------
  Update to ExtensionClass 4.2.1.