cleanup & refactor

Cleanup all the things. Major changes include:

*  <code>databases::postgresql</code> hates the way we install pg93, so hack around it
*  use yum_repository
*  use encrypted data bags
This directory should be less vagrant specific. I believe we've been opting for putting stuff under ``/opt/<appname>/virtual-env`` like in ``orvsd_central``. This breaks when you try to run it on the openstack TK config with the following:

```
       ================================================================================
       Error executing action `create` on resource 'python_virtualenv[/home/vagrant/venv]'
       ================================================================================
       
       
       ArgumentError
       -------------
       user vagrant doesn't exist
       
       
       Cookbook Trace:
       ---------------
       /tmp/kitchen/cookbooks/python/providers/virtualenv.rb:40:in `home'
       /tmp/kitchen/cookbooks/python/providers/virtualenv.rb:40:in `block (2 levels) in class_from_file'
       /tmp/kitchen/cookbooks/python/providers/virtualenv.rb:37:in `block in class_from_file'
```

The cookbook should also make sure it creates the directories and/or users if we don't assume root ownership.