Aiohttp-sqlalchemy

------------
**Added**

* Added support Python 3.7.

-----------
**Added**

* Support of `organized handlers in class
<https://docs.aiohttp.org/en/stable/web_quickstart.html#organizing-handlers-in-classes>`_
added to ``sa_decorator(key)``.

**Removed**

* Removed support of ``AsyncEngine`` type in ``sa_bind()`` signature. Use
``async_sessionmaker(engine, AsyncSession)`` or custom session factory returning
``AsyncSession`` instance.

-----------
**Changed**

* Rename first argument from ``arg`` to ``factory`` in ``sa_bind()`` signature.

**Deprecated**

* ``AsyncEngine`` type is deprecated in ``sa_bind()`` signature. Use
``async_sessionmaker(engine, AsyncSession)`` or custom session factory returning
``AsyncSession`` instance.

-----------
**Changed**

* Usage ``sqlalchemy.orm.sessionmaker`` instance is recomended as a first argument
for ``aiohttp_sqlalchemy.sa_bind()`` signature. See examples in documetation.

**Removed**

* Removed support of ``request.config_dict.get('sa_main')`` and
``request.app['sa_main']`` expressions. Use a ``request['sa_main'].bind`` expression.

-----------
**Added**

* Add support ``sqlalchemy.orm.sessionmaker`` as a first argument in function
``sa_bind(arg, key, middleware)``.

**Changed**

* Argument ``engine: AsyncEngine`` changed to ``arg: Union[AsyncEngine, sessionmaker]``
in ``sa_bind()`` signature.

**Deprecated**

* Deprecated support of ``request.config_dict.get('sa_main')`` and
``request.app['sa_main']`` expressions. Use a ``request['sa_main'].bind`` expression.

**Removed**

* Deprecated class ``views.SAViewMixin`` is removed. Use ``views.SAAbstractView``;
* Deprecated attribute ``SAView.sa_main_session`` is removed. Use method
``SAView.sa_session(key: str = 'sa_main')``.

-----------
**Removed**

* Deprecated function ``aiohttp_sqlalchemy.sa_engine()`` is removed. Use
``aiohttp_sqlalchemy.sa_bind()``.

**Deprecated**

* Undocumented class ``views.SAViewMixin`` is deprecated. Use ``views.SAAbstractView``.