Log Message:
Update py-flask-sqlalchemy to 2.2.

Version 2.2
-----------

Released on February 27, 2017, codename Dubnium

- Minimum SQLAlchemy version is 0.8 due to use of ``sqlalchemy.inspect``.
- Added support for custom ``query_class`` and ``model_class`` as args
  to the ``SQLAlchemy`` constructor. (`#328`_)
- Allow listening to SQLAlchemy events on ``db.session``. (`#364`_)
- Allow ``__bind_key__`` on abstract models. (`#373`_)
- Allow ``SQLALCHEMY_ECHO`` to be a string. (`#409`_)
- Warn when ``SQLALCHEMY_DATABASE_URI`` is not set. (`#443`_)
- Don't let pagination generate invalid page numbers. (`#460`_)
- Drop support of Flask < 0.10. This means the db session is always tied to
  the app context and its teardown event. (`#461`_)
- Tablename generation logic no longer accesses class properties unless they
  are ``declared_attr``. (`#467`_)

.. _#328: https://github.com/mitsuhiko/flask-sqlalchemy/pull/328
.. _#364: https://github.com/mitsuhiko/flask-sqlalchemy/pull/364
.. _#373: https://github.com/mitsuhiko/flask-sqlalchemy/pull/373
.. _#409: https://github.com/mitsuhiko/flask-sqlalchemy/pull/409
.. _#443: https://github.com/mitsuhiko/flask-sqlalchemy/pull/443
.. _#460: https://github.com/mitsuhiko/flask-sqlalchemy/pull/460
.. _#461: https://github.com/mitsuhiko/flask-sqlalchemy/pull/461
.. _#467: https://github.com/mitsuhiko/flask-sqlalchemy/pull/467