As a weekend project, I created a service to monitor the status of many services (Github included) in one single page http://isserviceup.com/ . You can register with your Github account and star the services you use to receive notifications through Slack when their status change. It's all free and open source, let me know your thoughts!
p.s. I just posted a Show HN here https://news.ycombinator.com/item?id=13117856