puppet: Use exec's 'creates' parameter instead of onlyif

(imported from commit 94b5e76ca5119443f143e4af5c86e3c16c99dc1e)

servers/puppet/modules/humbug/manifests/app_frontend.pp

@@ -34,7 +34,7 @@ class humbug::app_frontend {
 
   exec {"pip6":
     command  => "/usr/bin/pip install django-pipeline",
-    onlyif   => "test ! -d /usr/local/lib/python2.6/dist-packages/django-pipeline"
+    creates  => "/usr/local/lib/python2.6/dist-packages/django-pipeline"
   }
 
   # TODO: Add /usr/lib/nagios/plugins/check_send_receive_time ->

servers/puppet/modules/humbug/manifests/base.pp

@@ -11,23 +11,23 @@ class humbug::base {
   # FIXME: Stop using pip since it is insecure
   exec {"pip":
     command  => "/usr/bin/pip install django-jstemplate",
-    onlyif   => "test ! -d /usr/local/lib/python2.6/dist-packages/jstemplate"
+    creates  => "/usr/local/lib/python2.6/dist-packages/jstemplate"
   }
   exec {"pip2":
     command  => "/usr/bin/pip install markdown",
-    onlyif   => "test ! -d /usr/local/lib/python2.6/dist-packages/markdown"
+    creates  => "/usr/local/lib/python2.6/dist-packages/markdown"
   }
   exec {"pip3":
     command  => "/usr/bin/pip install requests",
-    onlyif   => "test ! -d /usr/local/lib/python2.6/dist-packages/requests"
+    creates  => "/usr/local/lib/python2.6/dist-packages/requests"
   }
   exec {"pip4":
     command  => "/usr/bin/pip install pika",
-    onlyif   => "test ! -d /usr/local/lib/python2.6/dist-packages/pika"
+    creates  => "/usr/local/lib/python2.6/dist-packages/pika"
   }
   exec {"pip5":
     command  => "/usr/bin/pip install South",
-    onlyif   => "test ! -d /usr/local/lib/python2.6/dist-packages/south"
+    creates  => "/usr/local/lib/python2.6/dist-packages/south"
   }
 
   group { 'humbug':

servers/puppet/modules/humbug/manifests/postgres.pp

@@ -52,5 +52,6 @@ class humbug::postgres {
 
   exec { "disable_logrotate":
     command => "/usr/bin/dpkg-divert --rename --divert /etc/logrotate.d/postgresql-common.disabled --add /etc/logrotate.d/postgresql-common",
+    creates => '/etc/logrotate.d/postgresql-common.disabled',
   }
 }