Render monthly transaction statistics for admins

Render the Statistics::MonthlyStatistics in a more visible place, rather
than requiring a developer to run the stats:show rake task.

app/controllers/admin/statistics_controller.rb

@@ -15,5 +15,7 @@ def index
     @comment_count = Comment.count
     @request_by_state = InfoRequest.group('described_state').count
     @tracks_by_type = TrackThing.group('track_type').count
+
+    @monthly_transactions = Statistics::MonthlyTransactions.new
   end
 end

app/views/admin/statistics/index.html.erb

@@ -80,3 +80,27 @@
     </div>
   </div>
 </div>
+
+<div class="row">
+  <div class="span12">
+    <h2>Transactions</h2>
+
+    <table class="table table-condensed table-hover">
+      <% @monthly_transactions.each_with_index do |row, index| %>
+        <tr>
+          <% if index.zero? %>
+            <% row.each do |cell| %>
+              <th style="text-orientation: sideways; writing-mode: vertical-lr;">
+                <%= cell %>
+              </th>
+            <% end %>
+          <% else %>
+            <% row.each do |cell| %>
+              <%= tag.td cell, class: { muted: cell.to_i.zero? } %>
+            <% end %>
+          <% end %>
+        </tr>
+      <% end %>
+    </table>
+  </div>
+</div>

spec/controllers/admin/statistics_controller_spec.rb

@@ -59,5 +59,11 @@
           "all_successful_requests" => 6,
           "all_new_requests" => 7 })
     end
+
+    it 'assigns the monthly transactions' do
+      get :index
+      expect(assigns[:monthly_transactions]).
+        to be_a(Statistics::MonthlyTransactions)
+    end
   end
 end