This is to address Cross-origin resource sharing (CORS) issue with Ajax

This before filter is to address Cross-origin resource sharing (CORS) issue with Ajax submission of contect form.
Solutions was found here: http://stackoverflow.com/questions/17027117/jquery-ajax-request-to-sinatra-app-blocked-by-cors
Before filters are evaluated before each request within the context of the request and can modify the request and response
Context for before filters in sinatra: http://www.sinatrarb.com/intro?name=filters#Filters