Assignment list only shows repos to repo owners

[ncbrown1]

Addition to #13: Make sure people (besides instructors and admins) are not able to see things they don't own or can't/shouldn't access.

By "owner" we do not mean the github owner, we mean:

• Those with "owner" privileges in the course organization
• Students whose github usernames appear in the repo name

[ncbrown1]

Solved in 0135a50e2e466972ba858c42093737c4818b95b1