Updating use of apt-key for Ansible

### 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In the README.md the instructions to install Ansible on Ubuntu are out of date, and no longer uses `apt-key`.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](https://manpages.debian.org/testing/apt/apt-key.8.en.html) for security reasons (on Debian, Ubuntu, and elsewhere). For more details, see [this AskUbuntu post](https://askubuntu.com/a/1307181). 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](https://docs.ansible.com/ansible/latest/installation_guide/installation_distros.html
)

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.