Enable passing csv_options to Roo::Csv, which are passed through to the underlying CSV call. Enable passing options through from Roo::Spreadsheet to Roo::Csv.
Enable passing the user and password to Roo::Google through an options hash, and pass it through from Roo::Spreadsheet.open as well.
Use attr_reader to expose Roo::Google#sheets by storing them in the @sheets ivar.
Drop defunct @filename ivar.
Drop mistaken autoload for RooRailsHelper - that module doesn't exist so the file should be required directly.