Need to have terminal-notifier installed.

brew install terminal-notifier

In your configuration file, use:

• notifier.notification-center.path = terminal-notifier binary path (default: terminal-notifier).
• notifier.notification-center.activate = Indicate which application should be activated when clicking on terminal-notifier message. See Info.plist file inside the application bundle to find the bundle identifier (key: CFBundleIdentifier). Leave empty if you don't want an application to be activated. For example to open iTerm2, use com.googlecode.iterm2 (default: com.apple.Terminal).
• notifier.notification-center.sound = Sound to play when the notification is fired. Use default to select the default sound. The possible names are listed in Sound Preferences (ls /System/Library/Sounds).