Asgineer

What's Changed
* make guide example work by tlovely in https://github.com/almarklein/asgineer/pull/37
* new black by almarklein in https://github.com/almarklein/asgineer/pull/38
* Fix 304s and more. by michaellenaghan in https://github.com/almarklein/asgineer/pull/41
* Update Python suppport by almarklein in https://github.com/almarklein/asgineer/pull/42

New Contributors
* tlovely made their first contribution in https://github.com/almarklein/asgineer/pull/37
* michaellenaghan made their first contribution in https://github.com/almarklein/asgineer/pull/41

**Full Changelog**: https://github.com/almarklein/asgineer/compare/v0.8.1...v0.8.2

Minor release, only marking Python 3.9 compatibility in trove-classifiers.

Better support for long-lived connections:
* Add support for sending responses using `request.accept()` and `request.send()`.
* That is now the recommended way to do chunked responses.
* This also provides support for long polling and SSE.
* Also add `RequestSet`, `request.sleep_while_connected()` and `request.wakeup()` for long polling and SSE.
* Websocket requests have a somewhat cleaner API.

Improved asset handler:
* Fix that HEAD requests on the asset handler util included the body in the response.
* Dont send compressed assets if compression does not help, and never compress videos.
* Fix/improve cache control header.

Further:
* Implement ASGI 3.0.
* More tests (full coverage for ws now too).
* Improved docs.

* Applied a [fix](https://github.com/almarklein/asgineer/pull/27) in `make_asset_handler()`

* Rename the project from "asgish" to "asgineer"!
* Various improvements to code and docs of `make_asset_handler()`.

* Add utils submodule with:
* `normalize_response()` for turning any response in a 3-tuple
* `make_asset_handler()` for serving in-memory static assets
* Fix CI for Daphne
* Make `request.host` return host name of the request.
* A few improvements and tweaks to code and docs.