Testing flow for saga and distributed bus publisher/consumer

[lifinsky]

Description
Current testing examples and documentation do not cover saga with distributed bus commands and events without real AMQP connection for unit testing or integration with in memory queue channel.

[benr77]

@dgafka told me a month or so ago that currently there is no support for testing DistributedBus. This would be a great addition. In the meantime you just need to mock it but it's not particularly elegant.

[dgafka]

Current testing examples and documentation do not cover saga

Saga can be tested, just as Aggregates using Ecotone Lite.
However there is not yet support for Distributed Bus