[Checkins] [zopefoundation/zope.testrunner] 332a3e: Appveyor: upgrade to latest pip

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/zopefoundation/zope.testrunner
  Commit: 332a3ef719ec81b83c5872c42f4b09e8c6476493
      https://github.com/zopefoundation/zope.testrunner/commit/332a3ef719ec81b83c5872c42f4b09e8c6476493
  Author: Marius Gedminas <marius at gedmin.as>
  Date:   2018-10-05 (Fri, 05 Oct 2018)

  Changed paths:
    M appveyor.yml

  Log Message:
  -----------
  Appveyor: upgrade to latest pip

Otherwise PowerShell converts pip's friendly warnings (printed to
stderr) about available newer versions to fatal errors.



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