Implements todo list for instance dashboard

app/views/admin/conference/_registrations.html.haml

@@ -0,0 +1,20 @@
+.well#registrations
+  .row
+    .text-center
+      %h4 Conference registrations over time
+  .row
+    .registrationsChart{"data-chart"=>"#{registrations.to_json}", "data-conferences"=>"#{conferences.to_json}", "data-weeks"=>"#{registration_weeks.to_json}"}
+      %canvas#registrationsChart{"data-name"=>"registrations"}
+  .row
+    .text-center
+      weeks
+  .row
+    .conferenceCheckboxes#registrationsCheckboxes
+      - conferences.each do |conference|
+        %div
+          %span{"style"=>"border-bottom: 3px solid #{conference.color};", "data-chart"=> "registrations"}
+            - if conference.pending?
+              %input{"type"=>"checkbox", "name"=>"#{conference.short_title}", "checked"=>"checked"}
+            - else
+              %input{"type"=>"checkbox", "name"=>"#{conference.short_title}"}
+            #{conference.short_title}