[Checkins] [zopefoundation/persistent] a2c300: Drop support for Python 3.4, add support for 3.8.

[Michael Howitz]

  Branch: refs/heads/py34,py38
  Home:   https://github.com/zopefoundation/persistent
  Commit: a2c3008f9272912d03f61235d4425870853f661f
      https://github.com/zopefoundation/persistent/commit/a2c3008f9272912d03f61235d4425870853f661f
  Author: Michael Howitz <mh at gocept.com>
  Date:   2019-04-24 (Wed, 24 Apr 2019)

  Changed paths:
    M .travis.yml
    M CHANGES.rst
    M appveyor.yml
    M setup.py
    M tox.ini

  Log Message:
  -----------
  Drop support for Python 3.4, add support for 3.8.