[Checkins] [zopefoundation/persistent] 4192cd: Force all CPython CI builds to require functioning...

[Jason Madden]

  Branch: refs/heads/issue131
  Home:   https://github.com/zopefoundation/persistent
  Commit: 4192cd3216a7bce89d68532b026f9fba4c40f231
      https://github.com/zopefoundation/persistent/commit/4192cd3216a7bce89d68532b026f9fba4c40f231
  Author: Jason Madden <jamadden at gmail.com>
  Date:   2020-02-21 (Fri, 21 Feb 2020)

  Changed paths:
    M .travis.yml
    M appveyor.yml
    M tox.ini

  Log Message:
  -----------
  Force all CPython CI builds to require functioning C extensions, and simplify tox.ini.