README.md: Clarify requirements note to add Ubuntu 16.04

README.md

@@ -4,7 +4,7 @@ Ansible playbook for base and initial configuration of the web server hosting my
 ## Assumptions
 Before you can run this, a few things are assumed:
 
-- You have a clean, minimal Debian 8 host up and running
+- You have a clean, minimal Debian 8 / Ubuntu 16.04 host up and running
 - You have a user account with password-less SSH access to the machine
 - You have sudo privileges on the remote host
 - You have created a `hosts` file with something like: