Merge pull request #3154 from consul/backport-check_for_deleted_proposals

[Backport] checks for deleted proposals

spec/features/admin/stats_spec.rb

@@ -137,6 +137,20 @@ feature 'Stats' do
       end
     end
 
+    scenario "Deleted proposals" do
+      proposal_notification = create(:proposal_notification)
+      proposal_notification.proposal.destroy
+
+      visit admin_stats_path
+      click_link "Proposal notifications"
+
+      expect(page).to have_css(".proposal_notification", count: 1)
+
+      expect(page).to have_content proposal_notification.title
+      expect(page).to have_content proposal_notification.body
+      expect(page).to have_content "Proposal not available"
+    end
+
   end
 
   context "Direct messages" do