Fix service_ensure.

We now test if service_ensure is 'running' or 'stopped' but it was
actually picking up the default value of ensure in params.pp which
was true, not present.

Fix this and thereby fix the failing test.

manifests/params.pp

@@ -1,6 +1,6 @@
 # PRIVATE CLASS: do not use directly
 class postgresql::params inherits postgresql::globals {
-  $ensure                     = true
+  $ensure                     = present
   $version                    = $globals_version
   $postgis_version            = $globals_postgis_version
   $listen_addresses           = 'localhost'

spec/unit/classes/server_spec.rb

@@ -101,7 +101,7 @@ describe 'postgresql::server', :type => :class do
 
     it 'should still enable the service' do
       should contain_service('postgresqld').with({
-        :ensure => true,
+        :ensure => 'running',
       })
     end
   end