Updating use of apt-key for Ansible

[edlee123]

Overview

In the README.md the instructions to install Ansible on Ubuntu are out of date, and no longer uses apt-key.

Upon reviewing the Ansible installation instructions, it was updated:

"Previously, you may have used apt-key add. This is now deprecated for security reasons (on Debian, Ubuntu, and elsewhere). For more details, see this AskUbuntu post. Also note that, for security reasons, we do NOT add the key to /etc/apt/trusted.gpg.d/ nor to /etc/apt/trusted.gpg where it would be allowed to sign releases from ANY repository."

Ansible Installation Guide

Instead they write:

$ sudo apt update
$ sudo apt install software-properties-common
$ sudo add-apt-repository --yes --update ppa:ansible/ansible
$ sudo apt install ansible

Acceptance Criteria

Update instruction to reflect deprecation of using apt-key add.