Added helper script for generate github releases

tool/gen-github-release.rb

@@ -0,0 +1,40 @@
+#!/usr/bin/env ruby
+
+require "bundler/inline"
+
+gemfile do
+  source "https://rubygems.org"
+  gem "octokit"
+  gem "faraday-retry"
+  gem "nokogiri"
+end
+
+require "open-uri"
+
+Octokit.configure do |c|
+  c.access_token = ENV['GITHUB_TOKEN']
+  c.auto_paginate = true
+  c.per_page = 100
+end
+
+client = Octokit::Client.new
+
+diff = client.compare("ruby/ruby", ARGV[0], ARGV[1])
+diff[:commits].each do |c|
+  if c[:commit][:message] =~ /\[Backport #(\d*)\]/
+    url = "https://bugs.ruby-lang.org/issues/#{$1}"
+    title = Nokogiri::HTML(URI.open(url)).title
+    title.gsub!(/ - Ruby master - Ruby Issue Tracking System/, "")
+  end
+
+  if c[:commit][:message] =~ /\(#(\d*)\)/
+    url = "https://github.com/ruby/ruby/pull/#{$1}"
+    title = Nokogiri::HTML(URI.open(url)).title
+    title.gsub!(/ · ruby\/ruby · GitHub/, "")
+  end
+
+  next unless url && title
+
+  puts "* [#{title}](#{url})"
+end
+