(MCO-833) Fix loading facts when YAML file contains aliases
(MCO-833) Fix loading facts when YAML file contains aliases

If YAML.safe_load is in use, we need to explicity enable aliases and
whitelisting Symbols classes. This
is needed for example by choria-mcollective which is creating
aliases for `libdir`.

puppetlabs/marionette-collective,puppetlabs/marionette-collective,puppetlabs/marionette-collective,puppetlabs/marionette-collective,puppetlabs/marionette-collective,puppetlabs/marionette-collective