[Checkins] [zopefoundation/grokcore.content] 155d7a: update buildout extends URL to the 3.0.0a1 tag

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/zopefoundation/grokcore.content
  Commit: 155d7abad6ad042f262ec819b92dbc6f447e1960
      https://github.com/zopefoundation/grokcore.content/commit/155d7abad6ad042f262ec819b92dbc6f447e1960
  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