[Checkins] [zopefoundation/zope.dublincore] 584885: Add Python 3.6, drop Python 3.3

[GitHub]

  Branch: refs/heads/py36
  Home:   https://github.com/zopefoundation/zope.dublincore
  Commit: 584885e40de12247818823268c6390dacb376138
      https://github.com/zopefoundation/zope.dublincore/commit/584885e40de12247818823268c6390dacb376138
  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.

Use modern badge locations in README.rst since the old one was broken.