[Checkins] [zopefoundation/Persistence] 83780a: Use a working Python 3.9

[Michael Howitz]

  Branch: refs/heads/py39
  Home:   https://github.com/zopefoundation/Persistence
  Commit: 83780a91324154b746c2b01463aaa97f26cb7bbb
      https://github.com/zopefoundation/Persistence/commit/83780a91324154b746c2b01463aaa97f26cb7bbb
  Author: Michael Howitz <mh at gocept.com>
  Date:   2020-02-12 (Wed, 12 Feb 2020)

  Changed paths:
    M .travis.yml

  Log Message:
  -----------
  Use a working Python 3.9