Uplink

==================
Added
-----
- The ``session`` property to the ``Consumer`` base class, exposing the
consumer instance's configuration and allowing for the persistence of
certain properties across requests sent from that instance.
- The ``params`` decorator, which when applied to a method of a ``Consumer``
subclass, can add static query parameters to each API call.
- The ``converters.Factory`` base class for defining integrations with
other serialization formats and libraries.
- The ``uplink.install`` decorator for registering extensions, such as a
custom ``converters.Factory`` implementation, to be applied broadly.

Fixed
-----
- Issue with detecting ``typing.List`` and ``typing.Dict`` for converting
collections on Python 3.7.
- ``RuntimeWarning`` that "``ClientSession.close`` was never awaited" when
using ``aiohttp >= 3.0``.

Changed
-------
- When using the ``marshmallow`` integration, Uplink no longer suppresses
``Schema`` validation errors on deserialization; users can now handle these
exceptions directly.

==================
Fixed
-----
- Issue with sending JSON list ``Body`` using ``json`` annotation.

==================
Fixed
-----
- When using ``uplink.AiohttpClient`` with ``aiohttp>=3.0``, the underlying
``aiohttp.ClientSession`` would remain open on program exit.

==================
Fixed
-----
- Issue where adding two or more response handlers (i.e., functions decorated
with ``uplink.response_handler``) to a method caused a ``TypeError``.

==================
Fixed
-----
- Applying ``returns.json`` decorator without arguments should produce JSON
responses when the decorated method is lacking a return value annotation.

==================
Added
-----
- Decorator ``uplink.returns.model`` for specifying custom return type without
indicating a specific data deserialization format.

Fixed
-----
- Have ``uplink.Body`` decorator accept any type, not just mappings.
- Reintroduce the ``uplink.returns`` decorator.