default to 'email' scope for okpy
default to 'email' scope for okpy

default scopes should be authentication-only

enolfc/oauthenticator,minrk/oauthenticator,NickolausDS/oauthenticator,jupyter/oauthenticator,jupyter/oauthenticator,jupyterhub/oauthenticator,maltevogl/oauthenticator