Update twine to 3.1.0

[pyup-bot]

This PR updates twine from 1.9.1 to 3.1.0.

Changelog

3.1.0

* :feature:`547` Add support for specifying ``--non-interactive`` as an
environment variable.

3.0.0

* :feature:`336` When a client certificate is indicated, all password
processing is disabled.
* :feature:`489` Add ``--non-interactive`` flag to abort upload rather than
interactively prompt if credentials are missing.
* :feature:`524` Twine now unconditionally requires the keyring library
and no longer supports uninstalling ``keyring`` as a means to disable
that functionality. Instead, use ``keyring --disable`` keyring functionality
if necessary.
* :feature:`518` Add Python 3.8 to classifiers.
* :bug:`332 major` More robust handling of server response in
``--skip-existing``

2.0.0

* :feature:`437` Twine now requires Python 3.6 or later. Use pip
9 or pin to "twine<2" to install twine on older Python versions.
* :bug:`491 major` Require requests 2.20 or later to avoid reported security
vulnerabilities in earlier releases.

1.15.0

* :feature:`488` Improved output on ``check`` command:
Prints a message when there are no distributions given to check.
Improved handling of errors in a distribution's markup, avoiding
messages flowing through to the next distribution's errors.

1.14.0

* :feature:`456` Better error handling and gpg2 fallback if gpg not available.
* :bug:`341 major` Fail more gracefully when encountering bad metadata
* :feature:`459` Show Warehouse URL after uploading a package
* :feature:`310` Now provide a more meaningful error on redirect during upload.

1.13.0

* :bug:`452 major` Restore prompts while retaining support for suppressing
prompts.
* :bug:`447 major` Avoid requests-toolbelt to 0.9.0 to prevent attempting to
use
openssl when it isn't available.
* :feature:`427` Add disable_progress_bar option to disable tqdm.
* :feature:`426` Allow defining an empty username and password in .pypirc.
* :bug:`441 major` Only install pyblake2 if needed.
* :bug:`444 major` Use io.StringIO instead of StringIO.
* :bug:`436 major` Use modern Python language features.
* :support:`439` Refactor tox env and travis config.
* :bug:`435 major` Specify python_requires in setup.py
* :bug:`432 major` Use https URLs everywhere.
* :bug:`428 major` Fix --skip-existing for Nexus Repos.
* :feature:`419` Support keyring.get_credential.
* :feature:`418` Support keyring.get_username_and_password.
* :bug:`421 major` Remove unnecessary usage of readme_render.markdown.
* :feature:`416` Add Python 3.7 to classifiers.
* :bug:`412 major` Don't crash if there's no package description.
* :bug:`408 major` Fix keyring support.

1.12.1

* :bug:`404` Fix regression with upload exit code

1.12.0

* :feature:`395 major` Add ``twine check`` command to check long description
* :feature:`392 major` Drop support for Python 3.3
* :feature:`363` Empower ``--skip-existing`` for Artifactory repositories
* :bug:`367 major` Avoid MD5 when Python is compiled in FIPS mode

1.11.0

* :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/>`_.

1.10.0

* :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

Links

• PyPI: https://pypi.org/project/twine
• Changelog: https://pyup.io/changelogs/twine/
• Docs: https://twine.readthedocs.io/

[coveralls]

Coverage increased (+0.06%) to 30.441% when pulling ada6f1c on pyup-update-twine-1.9.1-to-3.1.0 into 8613d9d on master.

[pyup-bot]

Closing this in favor of #359