Today, we are starting three brokers side-by-side, which include three Kafka instances and three zookeeper instances. That may be too much and may lead to unexpected issues.
This commit split the tests into three different modules:

• kafka verifies the typical Kafka behavior (producer, consumer, codecs...)
• kafka-ssl verifies the connection with SSL
• kafka-sasl verifies the connection with SASL

Each of them starts a single broker with a specific configuration.

In the meantime, I've added a native test for SASL and divided the messaging ITs into 2 groups (one specific to Kafka, and another one for AMQP and others).