[Checkins] [zopefoundation/z3c.checkversions] 051595: Enable required extra.

[GitHub]

  Branch: refs/heads/py37
  Home:   https://github.com/zopefoundation/z3c.checkversions
  Commit: 051595a592a975adc60b8f0f43dd6a06ff23b504
      https://github.com/zopefoundation/z3c.checkversions/commit/051595a592a975adc60b8f0f43dd6a06ff23b504
  Author: Michael Howitz <mh at gocept.com>
  Date:   2018-10-20 (Sat, 20 Oct 2018)

  Changed paths:
    M .travis.yml
    A setup.cfg

  Log Message:
  -----------
  Enable required extra.



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