only allow a site's repository admin to delete a site from within the Federalist app

[amirbey]

User Story

Background (Optional)

Acceptance Criteria

• [ ] Federalist receives notice that they are not an admin when attempting to delete a site for which they are not an admin
• [ ] Change made live via Federalist

After evaluating, edit this part:

Level of effort - <low/medium/high>

Implementation outline (if higher than "low" effort):

• [ ] remove permission for deleting site by an admin in the authorizers

[apburnes]

We need to figure this out.