HBS Demo Update

Updated to the latest keystone default theme

*Overview*

* Generated an entirely new keystone project as to have the latest keystone template code as the current template code is deprecated.
* Added support to externalize HSB helpers to their own file `views/templates/helpers/index.js` to avoid polluting the `keystone.js` with all the helper code.  
* Added helpers for date formatting, flash message, cloudindary url, category lists.  The Date and Category code mirror the functionality of Ghost.
* All pages now work [blog, posts, gallery, contact]
* Connected Flash Messages to display
* Added a gulp

*Todos*
Items to be address later.  Want to get the current HBS code reviewed and integrated into yeoman.
* More documentation
* Complete the additional Ghost HBS helpers to make Ghost Themes full-portable.