Fix retrieval of SNAPSHOT Studio artifact

When trying to retrieve Nuxeo studio artifact from Maven and using the "trunk" version (0.0.0-SNAPSHOT), Maven only retrieve the remote version the first time but nothing happens once the artifact is already in the local repository even if the project has changed in Nuxeo Studio and the jar is updated in the maven repository.

In our maven repository for studio, we need to add indexes indicating the last version available to maven clients.