Add simplebook ansible roles

Created by: slifty

This PR creates two categories of Ansible script for SimpleBook:

• Scripts to install the SimpleBook services.
• A role to install the SimpleBook plugin into a competition.

This PR does not actually install the SimpleBook plugin in a given competition.

To install SimpleBook in a competition (e.g. locally for testing):

1. replace - collection with - simplebook in the competition .yml file (e.g. competitions/LLIIA2020/ansible/LLIIA2020.yml).
2. Add simplebook_git_version: main to the appropriate inv/{scope}/group_vars/all.tmpl

Resolves #110 (closed)