Add readme template and update root readme

First stab at rules and guidelines for adding roles to this repo

README.md

 # ansible-roles
 
+Roles in this repo must be general purpose with all settings that can be set to a sensible default put in the defaults file.
+
+## Variables
+Any settings where a default makes no sense must assert the variable is set.
+
+## READMEs
+Every role in here must have a `README.md` based on the `template-role-README.md`
+
+## Check mode
+Roles here must be able to be run in check mode on an configured system
+
+## Changed
+
+Roles here must be able to be run on a configured system without returning any `changed` states. 
+ie. running the playbook twice once will configure the system the second will find everything working correctly
+
+## Lint
+
+Every role in here will be automatically linted by ansible-lint and must pass before being accepted here
+
+## Automatic testing
+
+>***TODO*** Every role here will be automatically tested on Ubuntu 16.04, 18.04 and CentOS 7 and must assert if it can't be run on one of these