Rename 'ConferenceController' to 'ConferencesController', and 'ProposalController' to 'ProposalsController'

app/views/admin/conferences/_recent_registrations.html.haml

@@ -0,0 +1,19 @@
+- if recent_registrations && !recent_registrations.empty?
+  .table-responsive
+    %table.table
+      %thead
+        %tr
+          %th #
+          %th Public Name
+          %th Conference
+          %th Date
+        - recent_registrations.each_with_index do |registration, index|
+          %tbody
+            %tr
+              %td= index + 1
+              %td= link_to registration.name, admin_user_path(registration.user.id)
+              %td= link_to registration.conference.title, admin_conference_path(registration.conference.short_title)
+              %td= registration.created_at.strftime('%m/%d/%Y')
+- else
+  %h5.text-warning.text-center
+    No registrations!