I was watching the Capacity Planning for Tableau Server session by Jeff Mills from Data15 and around the 33-minute mark he mentions a "Viz Crawler" tool that his team has posted to the Tableau Server Admin community.  Sounds like the tool can evaluate all the visualizations on a Tableau server to check if they can be rendered successfully or not.  I can't seem to locate this tool - can someone point me in the right direction?  We're planning an upgrade to our server installation and I'd like to run this tool on an upgraded non-production environment as part of our upgrade process.  Thanks!