Duplicate arguments in Query::Update to persist primary key

[bluetwin]

Query::Update deletes the primary key for def build_params

def build_params(args)
  @params = {klass.primary_key => args.delete(klass.primary_key), klass.resource_name => args}
end

Instead we can duplicate the args before deleting

def build_params(args)
  args = args.dup
  @params = {klass.primary_key => args.delete(klass.primary_key), klass.resource_name => args}
end

and keep the id when resource.update_attributes completes.