Update user_serializer.rb; remove puts

app/serializers/user_serializer.rb

-
 # Copyright (C) 2015 Centro de Computacao Cientifica e Software Livre
 # Departamento de Informatica - Universidade Federal do Parana
 #
@@ -38,7 +37,7 @@ class UserSerializer < ActiveModel::Serializer
 
   def role_ids
     roles = []
-    object.roles.each { |role| puts roles << role.id }
+    object.roles.each { |role| roles << role.id }
     roles
   end