Ensure we only define subunit worker packages once

We can only declare the packages once per node, but since we spin up
multiple workers per node, the definitions were being duplicated. This
fixes the worker.pp file to ensure we only define packages once.

Change-Id: Idc67f97b77b4f4be3864c9dacd3835bb8328d068

modules/subunit2sql/manifests/worker.pp

@@ -21,28 +21,38 @@ define subunit2sql::worker (
 ) {
   $suffix = "-${name}"
 
-  package { 'python-daemon':
-    ensure => present,
+  if ! defined(Package['python-daemon']) {
+    package { 'python-daemon':
+      ensure => present,
+    }
   }
 
-  package { 'python-zmq':
-    ensure => present,
+  if ! defined(Package['python-zmq']) {
+    package { 'python-zmq':
+      ensure => present,
+    }
   }
 
-  package { 'python-yaml':
-    ensure => present,
+  if ! defined(Package['python-yaml']) {
+    package { 'python-yaml':
+      ensure => present,
+    }
   }
 
-  package { 'gear':
-    ensure   => latest,
-    provider => 'pip',
-    require  => Class['pip'],
+  if ! defined(Package['gear']) {
+    package { 'gear':
+      ensure   => latest,
+      provider => 'pip',
+      require  => Class['pip'],
+    }
   }
 
-  package { 'statsd':
-    ensure   => latest,
-    provider => 'pip',
-    require  => Class['pip']
+  if ! defined(Package['statsd']) {
+    package { 'statsd':
+      ensure   => latest,
+      provider => 'pip',
+      require  => Class['pip']
+    }
   }
 
   file { '/usr/local/bin/subunit-gearman-worker.py':