Dashboard does not redirect to login screen even after the session is timed out

[anvithks]

Issue/Feature Description:
If the SODA Dashboard is left idle for a while, the authentication token gets expired in the keystone backend but the dashboard does not reflect the same. It remains active and allows user to perform actions for ex: create bucket, create profile etc.
On clicking the create button the API throws a 403 unauthorised error due to the token not being valid.

Why this issue to fixed / feature is needed(give scenarios or use cases):
Users should not be allowed to perform any actions if the session token is timed out. They should be logged out and prompted to login again.

How to reproduce, in case of a bug:

1. Login to the dashboard.
2. Leave it idle for 30 minutes or so
3. Try to register a backend or create a bucket.

Other Notes / Environment Information: (Please give the env information, log link or any useful information for this issue)
This issue is observed in #294 where more details can be seen.
Similar feature is requested in #570.