[#4604] Move method to model

lib/tasks/cache.rake

@@ -1,20 +1,8 @@
-require 'lockfile'
-
 namespace :rate_plugin do
   namespace :cache do
     desc "Update Time Entry cost caches"
     task :update_cost_cache => :environment do
-      Lockfile('update_cost_cache', :retries => 0) do
-        TimeEntry.all(:conditions => {:cost => nil}).each do |time_entry|
-          begin
-            time_entry.save_cached_cost
-          rescue Rate::InvalidParameterException => ex
-            puts "Error saving #{time_entry.id}: #{ex.message}"
-          end
-          
-        end
-        
-      end
+      Rate.update_all_time_entires_with_missing_cost
     end
   end
 end