Log Message:
py-acme py-certbot*: updated to 2.1.0

Certbot 2.1.0

Fixed

Interfaces which plugins register themselves as implementing without inheriting \ 
from them now show up in certbot plugins output.
IPluginFactory, IPlugin, IAuthenticator and IInstaller have been re-added to
certbot.interfaces.
This is to fix compatibility with a number of third-party DNS plugins which may
have started erroring with AttributeError in Certbot v2.0.0.
Plugin authors can find more information about Certbot 2.x compatibility
here.
A bug causing our certbot-apache tests to crash on some systems has been resolved.