def exclude(*args)
      e = flatten_list_of_strings(args)
      if e.nil? || e.empty?
        bot.exclude = []
      else
        bot.exclude += e
      end
    end
def exclude(*args)
      e = flatten_list_of_strings(args)
      if e.nil? || e.empty?
        bot.exclude = []
      else
        bot.exclude += e
      end
    end
specify list of strings we will check when deciding to respond
 to a tweet or not. accepts an array or a comma-delimited string.
 when called, any subsequent calls to search or replies will
 filter out tweets with these strings

 @param [Array, String] args list of usernames
 @example
   exclude "spam, junk, something"