Replace sib-oidc with solid-auth

1. run the a sib-app-data-server with djangoldp_account on branch solid-auth locally (ask @bleme if needed)
2. make sure the server is OK by running the server and test the solid auth demo on it : https://github.com/solid/solid-auth-client#demo-app
3. Code what's necessary on sib-auth ;)

Docs :https://solid.github.io/solid-auth-client/