calling URI.open via Kernel#open is deprecated, call URI.open directly

martinbaker.rb

# coding: utf-8
# martin bakerから助かった人の数を取得する
require 'rubygems'
require 'nokogiri'
require 'open-uri'
require 'date'

html = Nokogiri::HTML(URI.open('https://www.martin-baker.com/'))
count = html.search('h1>span')[0].text.to_i
date = Date.today.strftime("%Y/%m/%d")

puts "#{date}\t#{count}"