Rest Tools Loads Nothing

Steps to reproduce

1.  Add the rest-tools dependency to the Travel Demo project
2.  Start the project and open the Rest Tools app.
3. Assuming the API base path is set, nothing is displayed.
   

Expected results

1. The Swagger Ui is displayed with the Nodes endpoint documented.

Actual results

1. Nothing is displayed. The JSON endpoint the module adds, /.rest/swagger.json, is available.

Workaround

1. Nothing obvious

Development notes