Backend: Select a light-weight graphdb solution

[oubiwann]

Dgraph (I've used it before):

• https://github.com/dgraph-io/dgraph
• https://dgraph.io/docs/clients/raw-http/

Others:

• Just saw NebulaGraph (never heard of it).
• Used Janus before, as well as Orient ... both are painful to setup and maintain

[oubiwann]

Browsing here:

• https://db-engines.com/en/ranking/graph+dbms