By rendering the login page within the GET / path we cannot trap the /auth
location from horizon to allow us to setup kerberos and other REMOTE_USER tasks
on that path.
On initial unauthenticated request redirect the user to /auth/login.
Change-Id: Ibe577672fc67a33460ea5d8726925b7e4b2a65e9
Closes-Bug: #1418440