Edit machines.yml to use nested YAML data structures for box names. Edit Vagrantfile to reference updated YAML data appropriately.
Signed-off-by: Scott S. Lowe <scott.lowe@scottlowe.org>
Update the README.md file for multiple learning environments to reflect file name changes, changes in the process for using the learning environment, and changes in the supported/tested software versions.
Continue standardizing on `machines.yml` instead of `servers.yml` for external data file. Add multi-platform support to environments via provider overrides.
Add Ruby code to determine full path to supporting files referenced
in all Vagrantfiles. This will allow more effective use of Vagrant
commands when not in the same directory as the Vagrantfile.
