- Remove `ansible-galaxy` detection, since this command was introduced in Ansible 1.4.2 (December 2013). Checking for `ansible-playbook` presence should therefore be enough for any "modern" Ansible setup. - Look for the command defined by the new `playbook_command` option. Related to GH-7881 and GH-7536
Vagrant Core Plugins
These are plugins that ship with Vagrant. Vagrant core uses its own plugin system to power a lot of the core pieces that ship with Vagrant. Each plugin will have its own README which explains its specific role.