message: Update changelog, getting ready for release
diff: Changelog
  =========
  +0.13.4 (2020-10-27)
  +-------------------
  +
  +* `dotenv` is used for setting environment variables in development
  + environments.
  +* Added an API and simple interface for seeing OAuth2 clients and adding new
  + ones.
  +* Fixed a bug related to the OAuth2 `authorization_code` flow that prevented
  + completing the process if the user used an incorrect password the first time.
  +
  +
  0.13.3 (2020-10-03)
  -------------------
  