* Add a crawler argument to MiddlewareManager.__init__().
* Deprecate the spider argument in some MiddlewareManager subclasses.
* Remove the spider argument from ExecutionEngine.open_spider_async().
* Remove the spider argument from Scraper.open_spider().
* Fix the Scraper.close_spider() type hint.
* Remove the spider argument from Downloader internals.
* Deprecate the spider arg of download_func.
* Deprecate the spider arg of Downloader.fetch().
* Deprecate the spider arg of ItemPipelineManager.process_item().
* Fix pylint.
* Tests for MiddlewareManager spider code.
* Deprecated spider arg handling for custom pipeline managers.
* Add a test for the deprecated spider arg in a custom downloader.
* Remove TODO.
* Fix pylint.
* Switch TestEngineBase to mockserver.
* Split mockserver.py.
* Stop using WrappingFactory.
* Remove keyfile/certfile fields from TestHttpBase.
* Move webclient-only resources to test_webclient.py.
* Refactor MockServer.url().
* Migrate TestHttpBase to mockserver.
* Migrate TestSimpleHttpsBase to a separate mockserver.
* Rename TestHttpMockServerBase.
* Migrate TestHttpProxyBase to a separate mockserver.
* Refactor HTTP mockservers.
* Migrate to pytest-twisted (WIP)
* Some typing fixes.
* Make --reactor=asyncio the default again.
* Try installing the correct event loop policy in tests on Windows.
* Make reactor_pytest a normal fixture.
* Fix test warnings.
* Fix FTPDownloadHandler teardown.
* Cleanups, typing.
* More cleanup.
* Update only_asyncio/only_not_asyncio mark messages.
Andrey Rakhmatullin
Adrián Chaves
Emmanuel Rondan
Ammar Najjar