Catch import errors with HubAuth
Catch import errors with HubAuth

ellisonbg/nbgrader,jhamrick/nbgrader,ellisonbg/nbgrader,jhamrick/nbgrader,jupyter/nbgrader,jupyter/nbgrader,jupyter/nbgrader,jupyter/nbgrader,jupyter/nbgrader,jhamrick/nbgrader,ellisonbg/nbgrader,jhamrick/nbgrader,ellisonbg/nbgrader