Add Dict traitlet, github_to_nix_usernames_map
Add Dict traitlet, github_to_nix_usernames_map

luisfdez/oauthenticator,jupyterhub/oauthenticator,santi81/oauthenticator,yuvipanda/mwoauthenticator,NickolausDS/oauthenticator,santi81/oauthenticator,jupyter/oauthenticator,luisfdez/oauthenticator,maltevogl/oauthenticator,minrk/oauthenticator,yuvipanda/mwoauthenticator,jupyter/oauthenticator,enolfc/oauthenticator