GrimoireLab logs should be sent to Elasticsearch

[canasdiaz]

Debugging GrimoireLab is not easy as we force the user to read the logs file. Having the ELK deployed we can send the logs to Elasticsearch and allow our users to browse the logs using the UI. By doing this we will improve the way the users can debug the tool so we will have more feedback.

The aim of this Feature Request is to provide a way to get the logs in the ELK stack at least for the deployment done with the Docker Compose file. Everything must be open source as usual.