[Backend Dependencies Update] Update flask to 2.0.1

[pyup-bot]

This PR updates flask from 1.1.2 to 2.0.1.

Changelog

2.0.1

-------------

Released 2021-05-21

-   Re-add the ``filename`` parameter in ``send_from_directory``. The
 ``filename`` parameter has been renamed to ``path``, the old name
 is deprecated. :pr:`4019`
-   Mark top-level names as exported so type checking understands
 imports in user projects. :issue:`4024`
-   Fix type annotation for ``g`` and inform mypy that it is a namespace
 object that has arbitrary attributes. :issue:`4020`
-   Fix some types that weren't available in Python 3.6.0. :issue:`4040`
-   Improve typing for ``send_file``, ``send_from_directory``, and
 ``get_send_file_max_age``. :issue:`4044`, :pr:`4026`
-   Show an error when a blueprint name contains a dot. The ``.`` has
 special meaning, it is used to separate (nested) blueprint names and
 the endpoint name. :issue:`4041`
-   Combine URL prefixes when nesting blueprints that were created with
 a ``url_prefix`` value. :issue:`4037`
-   Roll back a change to the order that URL matching was done. The
 URL is again matched after the session is loaded, so the session is
 available in custom URL converters. :issue:`4053`
-   Re-add deprecated ``Config.from_json``, which was accidentally
 removed early. :issue:`4078`
-   Improve typing for some functions using ``Callable`` in their type
 signatures, focusing on decorator factories. :issue:`4060`
-   Nested blueprints are registered with their dotted name. This allows
 different blueprints with the same name to be nested at different
 locations. :issue:`4069`
-   ``register_blueprint`` takes a ``name`` option to change the
 (pre-dotted) name the blueprint is registered with. This allows the
 same blueprint to be registered multiple times with unique names for
 ``url_for``. Registering the same blueprint with the same name
 multiple times is deprecated. :issue:`1091`
-   Improve typing for ``stream_with_context``. :issue:`4052`

2.0.0

-------------

Released 2021-05-11

-   Drop support for Python 2 and 3.5.
-   Bump minimum versions of other Pallets projects: Werkzeug >= 2,
 Jinja2 >= 3, MarkupSafe >= 2, ItsDangerous >= 2, Click >= 8. Be sure
 to check the change logs for each project. For better compatibility
 with other applications (e.g. Celery) that still require Click 7,
 there is no hard dependency on Click 8 yet, but using Click 7 will
 trigger a DeprecationWarning and Flask 2.1 will depend on Click 8.
-   JSON support no longer uses simplejson. To use another JSON module,
 override ``app.json_encoder`` and ``json_decoder``. :issue:`3555`
-   The ``encoding`` option to JSON functions is deprecated. :pr:`3562`
-   Passing ``script_info`` to app factory functions is deprecated. This
 was not portable outside the ``flask`` command. Use
 ``click.get_current_context().obj`` if it's needed. :issue:`3552`
-   The CLI shows better error messages when the app failed to load
 when looking up commands. :issue:`2741`
-   Add :meth:`sessions.SessionInterface.get_cookie_name` to allow
 setting the session cookie name dynamically. :pr:`3369`
-   Add :meth:`Config.from_file` to load config using arbitrary file
 loaders, such as ``toml.load`` or ``json.load``.
 :meth:`Config.from_json` is deprecated in favor of this. :pr:`3398`
-   The ``flask run`` command will only defer errors on reload. Errors
 present during the initial call will cause the server to exit with
 the traceback immediately. :issue:`3431`
-   :func:`send_file` raises a :exc:`ValueError` when passed an
 :mod:`io` object in text mode. Previously, it would respond with
 200 OK and an empty file. :issue:`3358`
-   When using ad-hoc certificates, check for the cryptography library
 instead of PyOpenSSL. :pr:`3492`
-   When specifying a factory function with ``FLASK_APP``, keyword
 argument can be passed. :issue:`3553`
-   When loading a ``.env`` or ``.flaskenv`` file, the current working
 directory is no longer changed to the location of the file.
 :pr:`3560`
-   When returning a ``(response, headers)`` tuple from a view, the
 headers replace rather than extend existing headers on the response.
 For example, this allows setting the ``Content-Type`` for
 ``jsonify()``. Use ``response.headers.extend()`` if extending is
 desired. :issue:`3628`
-   The ``Scaffold`` class provides a common API for the ``Flask`` and
 ``Blueprint`` classes. ``Blueprint`` information is stored in
 attributes just like ``Flask``, rather than opaque lambda functions.
 This is intended to improve consistency and maintainability.
 :issue:`3215`
-   Include ``samesite`` and ``secure`` options when removing the
 session cookie. :pr:`3726`
-   Support passing a ``pathlib.Path`` to ``static_folder``. :pr:`3579`
-   ``send_file`` and ``send_from_directory`` are wrappers around the
 implementations in ``werkzeug.utils``. :pr:`3828`
-   Some ``send_file`` parameters have been renamed, the old names are
 deprecated. ``attachment_filename`` is renamed to ``download_name``.
 ``cache_timeout`` is renamed to ``max_age``. ``add_etags`` is
 renamed to ``etag``. :pr:`3828, 3883`
-   ``send_file`` passes ``download_name`` even if
 ``as_attachment=False`` by using ``Content-Disposition: inline``.
 :pr:`3828`
-   ``send_file`` sets ``conditional=True`` and ``max_age=None`` by
 default. ``Cache-Control`` is set to ``no-cache`` if ``max_age`` is
 not set, otherwise ``public``. This tells browsers to validate
 conditional requests instead of using a timed cache. :pr:`3828`
-   ``helpers.safe_join`` is deprecated. Use
 ``werkzeug.utils.safe_join`` instead. :pr:`3828`
-   The request context does route matching before opening the session.
 This could allow a session interface to change behavior based on
 ``request.endpoint``. :issue:`3776`
-   Use Jinja's implementation of the ``|tojson`` filter. :issue:`3881`
-   Add route decorators for common HTTP methods. For example,
 ``app.post("/login")`` is a shortcut for
 ``app.route("/login", methods=["POST"])``. :pr:`3907`
-   Support async views, error handlers, before and after request, and
 teardown functions. :pr:`3412`
-   Support nesting blueprints. :issue:`593, 1548`, :pr:`3923`
-   Set the default encoding to "UTF-8" when loading ``.env`` and
 ``.flaskenv`` files to allow to use non-ASCII characters. :issue:`3931`
-   ``flask shell`` sets up tab and history completion like the default
 ``python`` shell if ``readline`` is installed. :issue:`3941`
-   ``helpers.total_seconds()`` is deprecated. Use
 ``timedelta.total_seconds()`` instead. :pr:`3962`
-   Add type hinting. :pr:`3973`.

1.1.4

-------------

Released 2021-05-13

-   Update ``static_folder`` to use ``_compat.fspath`` instead of
 ``os.fspath`` to continue supporting Python < 3.6 :issue:`4050`

1.1.3

-------------

Released 2021-05-13

-   Set maximum versions of Werkzeug, Jinja, Click, and ItsDangerous.
 :issue:`4043`
-   Re-add support for passing a ``pathlib.Path`` for ``static_folder``.
 :pr:`3579`

Links

• PyPI: https://pypi.org/project/flask
• Changelog: https://pyup.io/changelogs/flask/
• Homepage: https://palletsprojects.com/p/flask