Add script to install oh my zhs in the terminal

[ferreiro]

https://gist.github.com/kevin-smets/8568070

brew cask install iterm2 && sh -c "$(curl -fsSL https://raw.github.com/robbyrussell/oh-my-zsh/master/tools/install.sh)" && git clone https://github.com/bhilburn/powerlevel9k.git ~/.oh-my-zsh/custom/themes/powerlevel9k && sudo echo'export ZSH_THEME="powerlevel9k/powerlevel9k"' >> ~/.zshrc