Foreman scenarios are lacking sane defaults

[mattock]

The Foreman scenarios (foreman_proxy and lcm) depended heavily on sane defaults stored in answer files. Now the answer files are empty, so the default values are missing. Add sane defaults which can be used reasonably in any environment.

A related problem is defaults for Vagrant, which can be considered a special environment with additional sane defaults. My proposed solution is this:

• Add generic, sane defaults to foreman_proxy.pp and lcm.pp
• Create an answer file suitable for the Vagrant environment
• Store and version the answer file
• Ensure that the default (almost empty) answer file is overwritten during Vagrant provisioning with the answer file tailored for Vagrant

This way Vagrant-specifisms don't accidentally end up in production environments.