Fixed env variables for public keycloak/gateway uri [WIP] added bin/wtl-dummy-dataset Fixed env variables for public keycloak/gateway uri into wtl-dummy-dataset [config] Updated repositories.example.yml added echo of $0 in the error message for wrong shell added bash to the supported values for $0 wikitolearn-coursessecurity-backend is in scratch, fixed reference

Signed-off-by: Toma Luca <toma.luca95@gmail.com>