[Checkins] [zopefoundation/RestrictedPython] 114ceb: Add Documentation for Python 3.9 AST changes (#201)

[Alexander Loechel]

  Branch: refs/heads/master
  Home:   https://github.com/zopefoundation/RestrictedPython
  Commit: 114ceba78829e92d6def991fb0288655f8564db9
      https://github.com/zopefoundation/RestrictedPython/commit/114ceba78829e92d6def991fb0288655f8564db9
  Author: Alexander Loechel <loechel at users.noreply.github.com>
  Date:   2020-10-12 (Mon, 12 Oct 2020)

  Changed paths:
    M .editorconfig
    M .travis.yml
    A docs/contributing/ast/python3_9.ast
    A docs/contributing/changes_from38to39.rst
    M docs/contributing/index.rst
    M tox.ini

  Log Message:
  -----------
  Add Documentation for Python 3.9 AST changes (#201)

* Editorconf
* Cleanup travis-ci
* changes to 3.9