Set up beacon database

DLM engine stores its state in the external relational database. You must configure an external database and add the DLM Engine database user to the database. Derby database is provided as an easy to use option in test or POC environments. It is strongly recommended to not use Derby for production usage. You must use mysql or postgresql. Make sure to configure backup for this database, so that the DLM state is not lost in case of database host failures.