Add sync certain user_names feature in rake.

lib/tasks/sync_asia_personal_data_tasks.rake

@@ -362,8 +362,12 @@ module AsiaSyncPlugin
 end
 namespace :sync_asia_personal_plugins do
   desc 'sync_personal_plugins from Asia'
-  task :sync => [:environment] do
-    users = User.all.to_a
+  task :sync,[:user_names] => [:environment] do |task,args|
+    if args.user_names
+      users = User.where(:user_name.in=>YAML.load(args.user_names)).to_a
+    else
+      users = User.all.to_a
+    end
     users.each do |user|
       puts "Fetching data for #{user.user_name}..."
       query_result = get_sync_data(user.user_name)