You need to use a third party piece of software to send messages to the Notification Center from command line tools and scripts.
terminal-notifier appears to be a popular solution. OSXDaily has an article walking through how to set terminal-notifier up.
Alternative methods are covered in the answers to, how can I trigger a Notification Center notification from an AppleScript or shell script?how can I trigger a Notification Center notification from an AppleScript or shell script?