Preparation of deployment for neon.ruby-lang.org

Just finished to preparation of deployment for neon.ruby-lang.org.

I created ```rubylang``` user and added vit-core team(@JEG2 @chikamichi @postmodern @stomar)'s public keys into authorized_keys. You can deploy after merge info master branch.

deployment is too easy capistrano task:

 * git clone git@github.com:ruby/www.ruby-lang.org.git
 * cd www.ruby-lang.org
 * cap deploy

Please check it.