[Checkins] [zopefoundation/grokcore.message] cb0016: update buildout extends URL to the 3.0.0a1 tag

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/zopefoundation/grokcore.message
  Commit: cb0016551568806f18ab70dd6c7ccad5f7eea33a
      https://github.com/zopefoundation/grokcore.message/commit/cb0016551568806f18ab70dd6c7ccad5f7eea33a
  Author: Jan-Wijbrand Kolman <jkolman at minddistrict.com>
  Date:   2018-01-22 (Mon, 22 Jan 2018)

  Changed paths:
    M buildout.cfg

  Log Message:
  -----------
  update buildout extends URL to the 3.0.0a1 tag