[Certbot-dev] Certbot 0.20.0 Release

[Brad Warren]

Certbot 0.20.0 has just been uploaded to PyPI. The changelog for this
release is:

### Added

* Certbot's ACME library now recognizes URL fields in challenge objects
in preparation for Let's Encrypt's new ACME endpoint. The value is still
accessible in our ACME library through the name "uri".

### Changed

* The Apache plugin now parses some distro specific Apache configuration
files on non-Debian systems allowing it to get a clearer picture on the
running Apache configuration.
* Certbot better reports network failures by removing information about
connection retries from the error output.
* An unnecessary question when using Certbot's webroot plugin
interactively has been removed.

### Fixed

* Certbot's NGINX plugin no longer sometimes incorrectly reports that it
was unable to deploy a HTTP->HTTPS redirect when requesting Certbot to
enable a redirect for multiple domains.
* An issue running the test shipped with Certbot and some our DNS
plugins with older versions of mock have been resolved.
* On some systems, users reported strangely interleaved output depending
on when stdout and stderr were flushed. This problem was resolved by
having Certbot regularly flush these streams.

More details about these changes can be found on our GitHub repo:
https://github.com/certbot/certbot/milestone/44?closed=1