Pin to posgresql 2.5 module

- Later version breaks backward compatibility.
- Sort fixtures for better maintainability

Change-Id: I30ac98687b4f6cedf241746f32d7d57678e6adbb

.fixtures.yml

@@ -1,17 +1,19 @@
 fixtures:
   repositories:
-    'keystone': 'git://github.com/stackforge/puppet-keystone.git'
     'cinder': 'git://github.com/stackforge/puppet-cinder.git'
+    'inifile':  'git://github.com/puppetlabs/puppetlabs-inifile'
+    'keystone': 'git://github.com/stackforge/puppet-keystone.git'
     'mysql':
       repo: 'git://github.com/puppetlabs/puppetlabs-mysql.git'
       ref: 'origin/0.x'
-    'stdlib': 'git://github.com/puppetlabs/puppetlabs-stdlib.git'
-    'sysctl': 'git://github.com/duritong/puppet-sysctl.git'
+    'postgresql':
+      repo: "git://github.com/puppetlabs/puppet-postgresql.git"
+      ref: '2.5.0'
+    'qpid': 'git://github.com/dprince/puppet-qpid.git'
     'rabbitmq':
       repo: 'git://github.com/puppetlabs/puppetlabs-rabbitmq'
       ref: 'origin/2.x'
-    'qpid': 'git://github.com/dprince/puppet-qpid.git'
-    'inifile':  'git://github.com/puppetlabs/puppetlabs-inifile'
-    'postgresql': 'git://github.com/puppetlabs/puppetlabs-postgresql.git'
+    'stdlib': 'git://github.com/puppetlabs/puppetlabs-stdlib.git'
+    'sysctl': 'git://github.com/duritong/puppet-sysctl.git'
   symlinks:
     'nova': "#{source_dir}"