Directors should only see the Dancers tab and the teams they direct.

[jessie-jin]

Issue:
Directors have too much access; they should only be able to see the Dancers tab and the Teams tab. Execs should be able to see everything: Dancers, Team Switch Requests, Teams, and Users.

Reproduction:
Login as an admin and you should be able to see all the tabs. Login as an director, and you should be able to see only the Dancers tab and the Teams, while the Team Switch Requests and Users tabs should be hidden.