Install terminal-notifier
via homebrew: https://github.com/julienXX/terminal-notifier
If using zsh, create an alias:
alias -g holler="echo 'holler' | terminal-notifier -sound default"
Store it in ./zshrc
if you're happy with it!
Now you can run
bundle exec rspec ; holler
and it will make a notification that says "holler" when your tests are done.