Update flask-sqlalchemy to 2.4.4

[pyup-bot]

This PR updates Flask-SQLAlchemy from 2.3.2 to 2.4.4.

Changelog

2.4.4

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

Released 2020-07-14

-   Change base class of meta mixins to ``type``. This fixes an issue
 caused by a regression in CPython 3.8.4. :issue:`852`

2.4.3

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

Released 2020-05-26

-   Deprecate ``SQLALCHEMY_COMMIT_ON_TEARDOWN`` as it can cause various
 design issues that are difficult to debug. Call
 ``db.session.commit()`` directly instead. :issue:`216`

2.4.2

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

Released 2020-05-25

-   Fix bad pagination when records are de-duped. :pr:`812`

2.4.1

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

Released 2019-09-24

-   Fix ``AttributeError`` when using multiple binds with polymorphic
 models. :pr:`651`

2.4.0

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

Released 2019-04-24

-   Make engine configuration more flexible. (:pr:`684`)
-   Address SQLAlchemy 1.3 deprecations. (:pr:`684`)
-   ``get_or_404()`` and ``first_or_404()`` now accept a ``description``
 parameter to control the 404 message. (:issue:`636`)
-   Use ``time.perf_counter`` for Python 3 on Windows. (:issue:`638`)
-   Drop support for Python 2.6 and 3.3. (:pr:`687`)
-   Add an example of Flask's tutorial project, Flaskr, adapted for
 Flask-SQLAlchemy. (:pr:`720`)

Links

• PyPI: https://pypi.org/project/flask-sqlalchemy
• Changelog: https://pyup.io/changelogs/flask-sqlalchemy/
• Repo: https://github.com/pallets/flask-sqlalchemy
• Docs: https://pythonhosted.org/Flask-SQLAlchemy/

[pyup-bot]

Closing this in favor of #82