6.0.0.M1

This is the first milestone release for 6.0.0. It introduces new metrics on published messages. This pre-release introduces also a breaking change which impacts users implementing the MetricsCollector interface in their applications. Users of the 5.x.x series are encouraged to test this version.

Changes between 5.x.x and 6.0.0.M1

Metrics for confirmed and unsuccessful outgoing publishes

The client now collects metrics on confirmed, failed, nacked, and unroutable outgoing messages. This change implies a change in the MetricsCollector interface. This is a breaking change for anyone implementing this interface in their application (which is unlikely to be).

Thanks to @slayful for this contribution.

GitHub PR: #354