Fix GPG key for yum.postgresl.org

The GPG key for yum.postgresql.org was in the wrong directory,
and as written, would have only supported postgres 9.2 anyway.

I looked at the yum rpms for a few other versions besides 9.2,
and they appear to be using the same GPG key.  So this commit
assumes that they all are doing so, and it sets things up
accordingly.  Hopefully this will make the yumrepo support
compatible with other versions of postgres besides 9.2, but I
haven't added that to the actual test matrix yet.

manifests/package_source/yum_postgresql_org.pp

@@ -6,7 +6,7 @@ class postgresql::package_source::yum_postgresql_org(
   $package_version     = "${version_parts[0]}${version_parts[1]}"
 
   file { "/etc/pki/rpm-gpg/RPM-GPG-KEY-PGDG-${package_version}":
-      source => "puppet:///modules/postgresql_tests/RPM-GPG-KEY-PGDG-${package_version}"
+      source => "puppet:///modules/postgresql/RPM-GPG-KEY-PGDG"
   } ->
 
   yumrepo { "yum.postgresql.org":