DEPRECATION WARNING: `Module#parent` has been renamed to `module_parent`. `parent` is deprecated and will be removed in Rails 6.1

[januszm]

With Rails 6, in

  def sass_importer_class
    @sass_importer_class ||= if defined?(self.class.parent::SassImporter)
                               self.class.parent::SassImporter

we'll need to change 2x class.parent to class.module_parent to remove the deprecation warning and prepare for Rails 6.1