Update gems, use d3 gem, initial bootstrap v3 port

app/views/conference_registration/_registration.html.haml

@@ -1,15 +1,15 @@
 .row
-  .span12
+  .col-md-12
     %h3
       Registration for
       = @conference.title
 - if @person.proposal_count(@conference) > 0
   .row
-    .span12
+    .col-md-12
       %i
         Please note: Registration is not automatically performed for speakers.  If you're scheduled to speak at the conference, you still need to register!
 .row
-  .span12
+  .col-md-12
     = f.inputs :name => "Your Details" do
       %br
       Your public name (required)
@@ -75,4 +75,4 @@
         onSelect: function(selected) {
             $("#registration-arrival-datepicker").datepicker("option","maxDate", selected)
         }
-    });
+    });