Not (Yet) Supported
This page contains an overview of not (yet) support applications or services with explanation as to why not.
Github though extensively used by some (potential) is not supported right now.
The main reason is the extensive list of IP addresses that must be opened that are non-dedicated (https://developer.github.com/v3/meta/). The implication is that by opening up all these IPs addresses, you are exposed to services that have nothing to do with Github and this provides an unnecessary risk.
We like to better understand the GitHub requirements to see if we can find a suitable solution. Feel free to contact me: firstname.lastname@example.org.