Update Drupal core and all dependencies to their latest version

[mheadd]

The current Drupal site template has dependencies that are out of date, as is the Drupal core version. All components should be updated to their latest versions.

Acceptance criteria

• [ ] composer.json file uses latest version of all components.
• [ ] Documentation demonstrates how to update Drupal core and dependencies as components become out of date,

Definition of done

• [ ] Base install using the artifacts in this directory provides a user with a Drupal site with all software components running current versions.

[onelittlebecca]

Do we want to refresh THIS example or start fresh?

[mheadd]

Good question. Do you think it would be easier to start from scratch, with a minimal, barebones install? I'm in favor of whatever path is easier.