Added shashankmehta's gitster theme
Added shashankmehta's gitster theme

Source at:
https://github.com/shashankmehta/dotfiles/blob/master/thesetup/zsh/.oh-my-zsh/custom/themes/gitster.zsh-theme

Irubataru/oh-my-zsh,Irubataru/oh-my-zsh,Irubataru/oh-my-zsh,Irubataru/oh-my-zsh