Fix visitor count. Mapping the session and making sure they were unique using rails was way slower than doing it with a mongoid query

lib/orbit_app/module/visitor_counter.rb

@@ -4,8 +4,7 @@ module OrbitApp
         Version = "0.1"
 
         def display_visitors(options={})
-          impressions = Impression.where(options).and(:referrer.ne => nil)
-          impressions.map{|i| i[:session_hash]}.uniq.count
+          impressions = Impression.where(options).and(:referrer.ne => nil).distinct(:session_hash).count
         end
 
         def display_visitors_today