Add Budgets Stats Controller, route and ability on reviewing ballots and finished budget

app/controllers/budgets/stats_controller.rb

@@ -0,0 +1,18 @@
+module Budgets
+  class StatsController < ApplicationController
+
+    load_and_authorize_resource :budget
+
+    def show
+      authorize! :read_stats, @budget
+      @stats = load_stats
+    end
+
+    private
+
+      def load_stats
+        Budget::Stats.new(@budget).generate
+      end
+
+  end
+end

app/models/abilities/everyone.rb

@@ -21,6 +21,7 @@ module Abilities
       can [:read], Budget::Group
       can [:read, :print, :json_data], Budget::Investment
       can [:read_results, :read_executions], Budget, phase: "finished"
+      can :read_stats, Budget, phase: ["reviewing_ballots", "finished"]
       can :new, DirectMessage
       can [:read, :debate, :draft_publication, :allegations, :result_publication,
            :proposals, :milestones], Legislation::Process, published: true

config/routes/budget.rb

@@ -15,6 +15,7 @@ resources :budgets, only: [:show, :index] do
   end
 
   resource :results, only: :show, controller: "budgets/results"
+  resource :stats, only: :show, controller: "budgets/stats"
   resource :executions, only: :show, controller: "budgets/executions"
 end