Only manage ssh dir if it isn't already managed.
Switch to new users class.
Fix user class and defines.
Revert drush-vagrant puppet module.
Issue #1909264: Support shell provisioning.
Move to librarian-puppet for managing Puppet modules.
Remove Git submodules for Symfony components, and switch to Composer.
Add back puppet-drush.
Add back apt puppet module, and update librarian-puppet files.
Remove Puppet submodules, since d.o won't package them. Add librarian-puppet files.
