* :bug:`269 major` Avoid uploading to PyPI when given alternate
repository URL, and require ``http://`` or ``https://`` in
``repository_url``.
* :support:`277` Add instructions on how to use keyring.
* :support:`314` Add new maintainer, release checklists.
* :bug:`322 major` Raise exception if attempting upload to deprecated legacy
PyPI URLs.
* :feature:`320` Remove PyPI as default ``register`` package index.
* :feature:`319` Support Metadata 2.1 (:pep:`566`), including Markdown
for ``description`` fields.
* :support:`318` `Update PyPI URLs
<https://packaging.python.org/guides/migrating-to-pypi-org/>`_.

* :bug:`315 major` Degrade gracefully when keyring is unavailable
* :feature:`304` Reorganize & improve user & developer documentation.
* :feature:`46` Link to changelog from ``README``
* :feature:`295` Add doc building instructions
* :feature:`296` Add architecture overview to docs
* :feature:`303` Revise docs predicting future of ``twine``
* :bug:`298 major` Fix syntax highlighting in ``README``
* :bug:`299 major` Fix changelog formatting
* :bug:`200 major` Remove obsolete registration guidance
* :bug:`286 major` Fix Travis CI and test configuration
* :feature:`257` Declare support for Python 3.6
* :bug:`297 major` Fix Read the Docs, tox, Travis configuration
* :bug:`268 major` Print progress to ``stdout``, not ``stderr``
* :bug:`265 major` Fix ``--repository[-url]`` help text
* :feature:`256` Improve progressbar