As you propose right on the main page to use the ppa:certbot/certbot for installation, I would highly recommend keeping the versions delivered by the paa up-to-date with your releases!
The paa offers version 0.11.1 on latest Ubuntu LTS (https://launchpad.net/~certbot/+archive/ubuntu/certbot?field.series_filter=xenial), although you already release version 0.13.0 (https://github.com/certbot/certbot/releases) 20 days ago.
Isn’t there a way to auto-update the ppa whenever a new release was created?
Though that bothered me when realizing it, Thanks for all your work, still !!!
Best from Munich