Ferran Rodenas

Create MongoDB dashboards & alerts

2

The [MongoDB dashboards](https://github.com/cloudfoundry-community/prometheus-boshrelease/tree/master/src/mongodb_dashboards) are currently empty and there is no job/package for MongoDB alerts.

There aren't any dashboards or alerts for `cadvisor` metrics.

Add smoke-tests so we can test that the final deploy succeed (ie alertmanager, prometheus and grafana)

There aren't any alert configured for system (`node_exporter`) metrics.