Update Ansible compatibility + support

[swalkinshaw]

• [x] I've read the guidelines for Contributing to Roots Projects
• [x] This request isn't a duplicate of an existing request
• [x] This is not a personal support request that should be posted on the Roots Discourse community

Summary

Trellis is pretty far behind on supporting Ansible versions. Ideally we stay more up to date on a regular basic, but in the meantime we should target supporting 4.x

https://docs.ansible.com/ansible/devel/reference_appendices/release_and_maintenance.html

Motivation

Why are we doing this? What use cases does it support? What is the expected outcome?

Additional context

Ansible also did some large updates around "collections" which we haven't done anything to properly support. Ref: https://docs.ansible.com/ansible/latest/user_guide/collections_using.html

[swalkinshaw]

https://github.com/roots/trellis/pull/1337 gets passed the first Ansible 2.11 compatibility issue at least.

Also the Ansible versioning world is very confusing right now. https://blog.while-true-do.io/ansible-release-3-0-0/ is a decent attempt to explain the insanity.

[swalkinshaw]

Trellis supports Ansible >= 2.10 now