- update to 20.1.0
- gevent and evenlet are BuildRequires for check
- add suggests
* document WEB_CONCURRENCY is set by, at least, Heroku
* capture peername from accept: Avoid calls to getpeername by capturing
the peer name returned by accept
* log a warning when a worker was terminated due to a signal
* fix tornado usage with latest versions of Django
* add support for python -m gunicorn
* fix systemd socket activation example
* allows to set wsgi application in configg file using wsgi_app
* document --timeout = 0
* always close a connection when the number of requests exceeds the max requests
* Disable keepalive during graceful shutdown
* kill tasks in the gthread workers during upgrade
* fix latency in gevent worker when accepting new requests
* fix file watcher: handle errors when new worker reboot and ensure
the list of files is kept
* document the default name and path of the configuration file
* document how variable impact configuration
* document the $PORT environment variable
* added milliseconds option to request_time in access_log
* added PIP requirements to be used for example
* remove version from the Server header
* fix sendfile: use socket.sendfile instead of os.sendfile
* reloader: use absolute path to prevent empty to prevent0 InotifyError
when a file is added to the working directory
* Add --print-config option to print the resolved settings at startup.
* remove the --log-dict-config CLI flag because it never had a working format