Download and run the install script:
curl https://raw.githubusercontent.com/rglassett/dotfiles/master/install.sh | sh
Alternatively, clone the repository, review/edit the dotfiles, and install manually.
If you don't already have rcm:
brew tap thoughtbot/formulae
brew install rcm
Then, to install:
git clone git@github.com:rglassett/dotfiles.git $HOME/.dotfiles
env RCRC=$HOME/.dotfiles/rcrc rcup
Much of this configuration is stolen from the Thoughtbot dotfiles repo.