Bug description

The link to notebook accepts security tokens gives a 404.

How to reproduce

Click on the link in this issue or go to BinderHub API documentation and click on the link. It's under the heading "Ready"

Expected behaviour

I expected to go to that page

Actual behaviour

Got a 404

Your personal set up

Obviously, the setup isn't really relevant for this issue.

• OS:

• Version(s):

# paste output of `pip freeze` or `conda list` here

# jupyterhub_config.py