Release version 0.4.0

• Initial implementation of the Zipkin exporter.
• Breaking change: Move B3 propagator to a contrib package
• Add support for Jaeger propagator
• Start implementing support for configuring exporters using Config pattern with support to load from environment variables and system properties.
• Add support to flush the entire SDK processors and exporter pipelines.
• Mark all threads/pools as daemon.
• Add support for Jaeger remote sampler.

Release version 0.3.0

• Initial Java API and SDK for context, trace, metrics, resource.
• Initial implementation of the Jaeger exporter.
• Initial implementation of the OTLP exporters for trace and metrics.

Release version 0.2.0

• First official release for OpenTelemetry Java.