Improve status controller

[aldoborrero]

Right now status controller is a fake service that will display ok in all networks (just to have Sparrow passing in their checks).

Would be awesome to think a good way of checking the status of the nodes.

Possible way of doing it is using docker healthcheck (https://howchoo.com/g/zwjhogrkywe/how-to-add-a-health-check-to-your-docker-container)

Also we should make sure that the checks are passing in tests.