[Checkins] [zopefoundation/zope.testrunner] dcfb1b: Add Python 3.8 to PyPI classifiers and appveyor

[Marius Gedminas]

  Branch: refs/heads/py38
  Home:   https://github.com/zopefoundation/zope.testrunner
  Commit: dcfb1bbe5011794c66df560f242d5d83763162e1
      https://github.com/zopefoundation/zope.testrunner/commit/dcfb1bbe5011794c66df560f242d5d83763162e1
  Author: Marius Gedminas <marius at gedmin.as>
  Date:   2020-05-13 (Wed, 13 May 2020)

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

  Log Message:
  -----------
  Add Python 3.8 to PyPI classifiers and appveyor

Simplify .travis.yml, dist: xenial has been the default for a while now.