add index on user_visits for reports

db/migrate/20150707163251_add_reports_index_to_user_visits.rb

@@ -0,0 +1,9 @@
+class AddReportsIndexToUserVisits < ActiveRecord::Migration
+  def up
+    add_index :user_visits, [:visited_at, :mobile]
+  end
+
+  def down
+    remove_index :user_visits, [:visited_at, :mobile]
+  end
+end