def formatters(io)
      fmts = [Airbrussh::ConsoleFormatter.new(io, self)]
      fmts.unshift(Airbrussh::LogFileFormatter.new(log_file)) if log_file
      fmts
    end
def formatters(io)
      fmts = [Airbrussh::ConsoleFormatter.new(io, self)]
      fmts.unshift(Airbrussh::LogFileFormatter.new(log_file)) if log_file
      fmts
    end
This returns an array of formatters appropriate for the configuration.
 Depending on whether a log file is configured, this could be just the
 Airbrussh:ConsoleFormatter, or that plus the LogFileFormatter.