puppet: Add uid/gid for Nagios user.

It turns out that having a UID for one user that's 1000, and not
setting them for other users, is a disaster: puppet might create them
in the wrong order, using UID 1000, and thus breaking creating the
'humbug' user later on.  The same issue applies to groups.

(imported from commit 02b4700278e5c495bd514802f41ae238e6b051ac)

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

@@ -92,14 +92,14 @@ class humbug::base {
     mode       => 644,
   }
 
-  # TODO: We may or may not want to enforce a set UID/GIT for the
-  # nagios user like we do for the humbug user; we don't do that here
-  # because those values differ widely between our existing systems
-  # (some are "system" users with uids around 100, some have uids
-  # around 1000, some have their own group, some are in the nogroup
-  # group, etc.).
+  group { 'nagios':
+    ensure     => present,
+    gid => '1050',
+  }
   user { 'nagios':
     ensure     => present,
+    uid        => '1050',
+    gid        => '1050',
     shell      => '/bin/bash',
     home       => '/home/nagios',
     managehome => true,