Missing supported_os fact

If the supported_os fact is missing, the test will not run on the
default supported systems (debian, ubuntu, centos).

Change-Id: Ifaa3da741778f3f2af00e82934235f44dd0cf24e

spec/classes/barbican_wsgi_apache_spec.rb

@@ -97,6 +97,7 @@ describe 'barbican::wsgi::apache' do
   end
 
   on_supported_os({
+    :supported_os => OSDefaults.get_supported_os
   }).each do |os,facts|
     let (:facts) do
       facts.merge!(OSDefaults.get_facts({