upgrade bundler version

While I was deploying kayak, I got this message:

  [kayak.test] sh -c 'cd /u/apps/kayak/current && bundle install --gemfile /u/apps/kayak/current/Gemfile --path /u/apps/kayak/shared/bundle --deployment --quiet --without development test'
  ** [out :: kayak.test] OpenSSL::SSL::SSLError: SSL_connect SYSCALL returned=5 errno=0 state=SSLv3 read server session ticket A
  ** [out :: kayak.test] An error occurred while installing rake (0.9.2.2), and Bundler cannot continue.
  ** [out :: kayak.test] Make sure that `gem install rake -v '0.9.2.2'` succeeds before bundling.