Logout doesn't navigate to root page

[justinpombrio]

Logging out should always navigate to http://captain-teach.cs.brown.edu. Instead, when I log out from http://captain-teach.cs.brown.edu/submitted, the url stays the same, producing the error message:

The page you were looking for doesn't exist.
You may have mistyped the address or the page may have moved.
If you are the application owner check the logs for more information.