New Keycloak installation

Workflow

Download and Unzip Keycloak distribution
start it with standalone.sh script
create admin user (on older installations - “admin”, on newer - “superadministrator”)
login to the Administration Console
create a new realm “avril-realm”
- copy all parameters from an older installation (on newer installation is possible to make an import)
- create roles
  - user
  - admin
  - superadmin
- create clients (on older keycloak “applications”)
  - avril-web
  - avril-backend
blubb

AdminClient.createUser() doesn't work because user.credential() doesn't exist any more
AdminClient.requestTokenRefresh() doesn't work any more because the constant ServiceUrlConstants.TOKEN_SERVICE_REFRESH_PATH doesn't exist any more