Add fact to report FreeRADIUS version number

lib/facter/freeradius_version.rb

+# Grab the FreeRADIUS version from the output of radiusd -v
+Facter.add(:freeradius_version) do
+  setcode do
+    Facter::Core::Execution.exec('radiusd -v').split(/\n/)[0].match(/FreeRADIUS Version (\d\.\d\.\d)/)[1]
+  end
+end
+