Change open uri http://... to https://...

## 環境

- Ruby 1.9.3-p385
- Debian GNU/Linux 6.0.6 (squeeze)

## 修正対象

news.ycombinator.com/news が http → https リダイレクトするようになったらしく、
下記エラーが発生して記事一覧が取得できていませんでした。

    #<RuntimeError: redirection forbidden: http://news.ycombinator.com/news -> https://news.ycombinator.com/news>
           /home/gongo/.rbenv/versions/1.9.3-p385/lib/ruby/1.9.1/open-uri.rb:216:in `open_loop'
           /home/gongo/.rbenv/versions/1.9.3-p385/lib/ruby/1.9.1/open-uri.rb:146:in `open_uri'
           /home/gongo/.rbenv/versions/1.9.3-p385/lib/ruby/1.9.1/open-uri.rb:677:in `open'
           /home/gongo/.rbenv/versions/1.9.3-p385/lib/ruby/1.9.1/open-uri.rb:33:in `open'
           /home/gongo/service/hackway/lib/hackway/session.rb:48:in `monitoring'
           /home/gongo/service/hackway/lib/hackway/session.rb:33:in `block (2 levels) in on_user'
           /home/gongo/service/hackway/lib/hackway/session.rb:31:in `loop'
           /home/gongo/service/hackway/lib/hackway/session.rb:31:in `block in on_user'