Features
* [1887](https://github.com/huge-success/sanic/pull/1887) Pass subprotocols in websockets (both sanic server and ASGI)
* [1894](https://github.com/huge-success/sanic/pull/1894) Automatically set `test_mode` flag on app instance
* [1903](https://github.com/huge-success/sanic/pull/1903) Add new unified method for updating app values
* [1906](https://github.com/huge-success/sanic/pull/1906), [#1909](https://github.com/huge-success/sanic/pull/1909) Adds WEBSOCKET_PING_TIMEOUT and WEBSOCKET_PING_INTERVAL configuration values
* [1935](https://github.com/huge-success/sanic/pull/1935) httpx version dependency updated, it is slated for removal as a dependency in v20.12
* [1937](https://github.com/huge-success/sanic/pull/1937) Added auto, text, and json fallback error handlers (in v21.3, the default will change form html to auto)
Bugfixes
* [1897](https://github.com/huge-success/sanic/pull/1897) Resolves exception from unread bytes in stream
Deprecations and Removals
* [1903](https://github.com/huge-success/sanic/pull/1903) config.from_envar, config.from_pyfile, and config.from_object are deprecated and set to be removed in v21.3
Developer infrastructure
* [1890](https://github.com/huge-success/sanic/pull/1890), [#1891](https://github.com/huge-success/sanic/pull/1891) Update isort calls to be compatible with new API
* [1893](https://github.com/huge-success/sanic/pull/1893) Remove version section from setup.cfg
* [1924](https://github.com/huge-success/sanic/pull/1924) Adding --strict-markers for pytest
Improved Documentation
* [1922](https://github.com/huge-success/sanic/pull/1922) Add explicit ASGI compliance to the README