Backlog/112

Mainly implements issue https://github.com/telefonicaid/fiware-connectors/issues/112.

It implements issue https://github.com/telefonicaid/fiware-connectors/issues/104 as well.
I would say:

"Informational messages such as Cygnus version, transaction start/end, and other are labeled as <i>Informational</i>, being `INFO` the logging level"

as I think transaction start/end is a quite relevant case of INFO message.