Not all members of the org, have admin access

[orta]

Both danger and Gatsby auto-invite folks to the org, if we use that as a metric for having access to edit peril settings - then both can have anyone edit the settings - not great.

There could be:

• A GitHub group you can set up for admins only
• A check if you're an admin for that org?
• A list of names

[orta]

When asking for installations you find out if you have read/write/admin to the org - we could do something here: https://developer.github.com/v3/apps/installations/