Add haml gem and bundle

I'm about to build the BH3 Marathon rego web page and it occurred to me that I'd like to use HAML for the view and for all views, moving forward. That said, HAML isn't universal and it may make it more difficult for the next sucker(s) who end up working on the site. What do you think? 

If you want to move forward with HAML, I'd also plan to convert all current views since there are automagic ways to do so.