Changed repo check from operatingsystem to osfamily

Due to the large number of RHEL clones it's simpler to use osfamily. In
my use case Scientific Linux wasn't mentioned and thus the module failed
in my environment.
Also did the same for Debian to be consistent.
Fixed tests for repos using osfamily

Tests needed to be updated to use osfamily fact rather than operating
system.
Merge pull request #173 from george-b/os_family

Changed repo check from operatingsystem to osfamily