[Checkins] [zopefoundation/zope.dublincore] 681cc3: Add Python 3.6, drop Python 3.3

[GitHub]

  Branch: refs/heads/py36
  Home:   https://github.com/zopefoundation/zope.dublincore
  Commit: 681cc33aed4a53d647f266402f41cf6ccf9e69ae
      https://github.com/zopefoundation/zope.dublincore/commit/681cc33aed4a53d647f266402f41cf6ccf9e69ae
  Author: Jason Madden <jamadden at gmail.com>
  Date:   2017-07-25 (Tue, 25 Jul 2017)

  Changed paths:
    A .coveragerc
    M .travis.yml
    M CHANGES.rst
    M MANIFEST.in
    M README.rst
    M docs/narrative.rst
    M setup.cfg
    M setup.py
    M tox.ini

  Log Message:
  -----------
  Add Python 3.6, drop Python 3.3

Also be sure that the doctests are run on CI and in tox. Make them
work for all versions of Python.