Implements #150

Adds an entry inside moderation section that allows moderators to check
pending tasks and mark them as solved.

config/routes/moderation.rb

@@ -27,4 +27,6 @@ namespace :moderation do
     put :hide, on: :member
     put :moderate, on: :collection
   end
+
+  resources :administrator_tasks, only: %i[index edit update]
 end