Fix facts for nova::keystone::auth test

We've recently started using additional facts in the cinder module so we
need to ensure they have the proper information in our spec tests.
Eventually this needs to get moved to rspec-puppet-facts instead of
being defined here.

Change-Id: Ia8bb4a98e80ecab18a4748cf4cf38152570618e1

spec/classes/nova_keystone_auth_spec.rb

@@ -132,7 +132,10 @@ describe 'nova::keystone::auth' do
     end
 
     let :facts do
-      @default_facts.merge({ :osfamily => "Debian"})
+      @default_facts.merge({
+        :osfamily => "Debian",
+        :os       => { :name  => 'Debian', :family => 'Debian', :release => { :major => '8', :minor => '0' } },
+      })
     end
 
     let :params do