def update_attributes!(attributes)
      attributes.each { |attribute, value| write_attribute(attribute, value) }
      save!
    end
def update_attributes!(attributes)
      attributes.each { |attribute, value| write_attribute(attribute, value) }
      save!
    end
Updates multiple attributes at once, saving the object once the updates are complete.
 Raises a Dynamoid::Errors::DocumentNotValid exception if there is vaidation and it fails.

 @param [Hash] attributes a hash of attributes to update