Log Message:
security/py-{acme,certbot}: Update to 0.24.0.

### Added

- certbot now has an enhance subcommand which allows you to configure
  security enhancements like HTTP to HTTPS redirects, OCSP stapling,
  and HSTS without reinstalling a certificate.
- certbot-dns-rfc2136 now allows the user to specify the port to use
  to reach the DNS server in its credentials file.
- acme now parses the wildcard field included in authorizations so it
  can be used by users of the library.

### Changed

- certbot-dns-route53 used to wait for each DNS update to propagate
  before sending the next one, but now it sends all updates before
  waiting which speeds up issuance for multiple domains dramatically.
- We've doubled the time Certbot will spend polling authorizations
  before timing out.
- The level of the message logged when Certbot is being used with
  non-standard paths warning that crontabs for renewal included in
  Certbot packages from OS package managers may not work has been
  reduced. This stops the message from being written to stderr every
  time `certbot renew` runs.

### Fixed

- certbot-auto now works with Python 3.6.