Fluentd support for transport service logging

We have integrated fluentd in the backend-client's logging and this could be ported to the transport service as well. 

The benefit is that we can then stream the logs to a fluentd host and then process or visualize them on our kibana dashboards.

https://github.com/wirepas/backend-client/blob/master/wirepas_backend_client/tools/logs.py