Prerequisites
I assume you're on a Mac, currently with Mac OS X El Capitan (10.11).
You need:
clone & setup
brew install zsh # I assume you're on a Mac
chsh -s `which zsh`
git clone --recursive https://github.com/kleinmann/dotfiles.git ~/.dotfiles
cd ~/.dotfiles
install rbenv
brew install rbenv ruby-build
rbenv install 2.2.3
rbenv global 2.2.3
~/.rbenv/shims/gem install bundler
initialize
cd ~/.dotfiles
brew install gnupg
~/.rbenv/shims/bundle
rake install
vim +PlugInstall +qall
brew tap Homebrew/bundle
cd ~/.dotfiles
brew bundle