Replace Ansible base with Ansible core

[alessfg]

Proposed changes

Replace Ansible base with Ansible core. Ansible core will be the "core" Ansible release moving forward from Ansible 2.11.

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING document
• I have added Molecule tests that prove my fix is effective or that my feature works
• I have checked that any relevant Molecule tests pass after adding my changes
• I have updated any relevant documentation (defaults/main.yml, README.md and CHANGELOG.md)