Do not generate postmap when postfix::map ensure is absent (#178)

manifests/map.pp

@@ -47,7 +47,11 @@ define postfix::map (
   if $type =~ /^(cidr|pcre)$/ {
     $manage_notify = Service['postfix']
   } else {
+    if $ensure == 'present' {
       $manage_notify = Exec["generate ${name}.db"]
+    } else {
+      $manage_notify = undef
+    }
   }
 
   file { "postfix map ${name}":

spec/defines/postfix_map_spec.rb

@@ -91,6 +91,7 @@ describe 'postfix::map' do
         } }
 
         it { is_expected.to contain_file('postfix map foo').with_ensure('absent') }
+        it { is_expected.to contain_file('postfix map foo').without_notify }
         it { is_expected.to contain_file('postfix map foo.db').with_ensure('absent') }
         it { is_expected.to contain_exec('generate foo.db') }
       end