[Checkins] [zopefoundation/zope.schema] a2a86f: Make the resolution order of all fields consistent.

[Jason Madden]

  Branch: refs/heads/issue80
  Home:   https://github.com/zopefoundation/zope.schema
  Commit: a2a86f064a64a86f1bd29a6c0830f9cf8eeaeeac
      https://github.com/zopefoundation/zope.schema/commit/a2a86f064a64a86f1bd29a6c0830f9cf8eeaeeac
  Author: Jason Madden <jamadden at gmail.com>
  Date:   2020-03-20 (Fri, 20 Mar 2020)

  Changed paths:
    M .gitignore
    M .travis.yml
    M CHANGES.rst
    M setup.py
    M src/zope/schema/_field.py
    M src/zope/schema/accessors.py
    M src/zope/schema/tests/test__bootstrapfields.py
    M src/zope/schema/tests/test__field.py
    M src/zope/schema/tests/test_accessors.py
    M tox.ini

  Log Message:
  -----------
  Make the resolution order of all fields consistent.

And test this. Fixes #80.

Add Python 3.8, drop Python 3.4.