(maint) Fix spec failures resulting from Facter API changes

(maint) Fix spec failures resulting from Facter API changes

Without this patch stdlib tests fail against Facter 2.x and master but
not 1.6.x.

This patch fixes the problem by initializing the example group
differently depending on the version of Facter integrating into the
system.  The adjusted methods are:

 1.x - Facter.collection.loader.load
 2.x - Facter.collection.load

The collection actually implements the load method in both version, it's
simply marked as private in 1.x.