In following https://docs.chef.io/release/delivery/integrate_delivery_github.html
It would be nice to clarify what "Roles Within the Enterprise" we should set:
observer
shipper
reviewer
committer
admin
Hi Hippie hacker! 
I can help you understand what does each role do within an Enterprise (https://docs.chef.io/delivery_users_and_roles.html) and with that, we would like you to decide what is the right role(s) for each users within your Organization. (your company, not the Delivery Org)
For the Github Integration or any other one, the roles doesn’t change. That means that you will treat them as the documentation describes.
If this is not clear yet, we would like you to describe what kind of user are you trying to create and we might be able to recommend you the roles you should configure.
Salim Afiune