def file_key_in_format(file_name, format)
      if format == "gzip"
        self.class.s3_file_key exporter.source_table, gzipped(file_name)
      else
        self.class.s3_file_key exporter.source_table, file_name
      end
    end
def file_key_in_format(file_name, format)
      if format == "gzip"
        self.class.s3_file_key exporter.source_table, gzipped(file_name)
      else
        self.class.s3_file_key exporter.source_table, file_name
      end
    end
Returns the s3 key to be used
 @return [String] file key with extension