The Monasca Log Transformer takes raw, unstandardised logs from one
Kafka topic, standardises them with whatever rules the operator wants
to use, and then writes them to a standardised logs topic in Kafka. It
is currently implemented as a Logstash config file.

Since Kolla does a fairly good job of standardising logs, this service
does very little processing. However, when other sources of logs
are used, it may be useful to add rules to the Transformer, particularly
if it's not possible to standardise the logs at source.

Ingesting the logs from this service with Fluentd will be covered under
a different commit.

Change-Id: I31cbb7e9a40a848391f517a56a67e3fd5bc12529
Partially-Implements: blueprint monasca-roles