[Checkins] [zopefoundation/zope.testrunner] 0a7dde: Make the 'subunit' support purely optional.

[GitHub]

  Branch: refs/heads/make-subunit-optional
  Home:   https://github.com/zopefoundation/zope.testrunner
  Commit: 0a7dde5d6129326509561d947d491fa4d5bd35f3
      https://github.com/zopefoundation/zope.testrunner/commit/0a7dde5d6129326509561d947d491fa4d5bd35f3
  Author: Tres Seaver <tseaver at palladion.com>
  Date:   2016-07-07 (Thu, 07 Jul 2016)

  Changed paths:
    M .travis.yml
    M CHANGES.rst
    M setup.py
    M src/zope/testrunner/tests/testrunner-subunit.txt
    M tox.ini

  Log Message:
  -----------
  Make the 'subunit' support purely optional.

Applications which have been getting the dependencies via 'zope.testrunner'
should either add 'zope.testrunner[subunit]' to their 'install_requires',
or else depend directly on 'python-subunit'.