No immediate impact to sleuth, but some notable changes underneath: * zipkin.Sampler is now extensible to permit dynamic rate adjustments * self-tracing can now be disabled even if Brave is in the classpath * related property: zipkin.self-tracing.enabled * brave-spancollector-scribe is no longer an optional dependency In the world of plugins: * Elasticsearch bugfix on traces w/ more than 10 spans * New ZooKeeper adaptive collection-tier sampler