[Checkins] [zopefoundation/zope.globalrequest] eaa535: Travis: upgrade pip to latest. Maybe fixes 3.4 build.

[Maurits van Rees]

  Branch: refs/heads/maurits/tox-py38
  Home:   https://github.com/zopefoundation/zope.globalrequest
  Commit: eaa535644b879185d4dc5b1cb0cb679bf7f9fd5d
      https://github.com/zopefoundation/zope.globalrequest/commit/eaa535644b879185d4dc5b1cb0cb679bf7f9fd5d
  Author: Maurits van Rees <maurits at vanrees.org>
  Date:   2020-03-28 (Sat, 28 Mar 2020)

  Changed paths:
    M .travis.yml

  Log Message:
  -----------
  Travis: upgrade pip to latest. Maybe fixes 3.4 build.