Release 0.5.0 (nats-io#71)

Release 0.5.0

[maven-release-plugin] copy for tag 0.4.1

[maven-release-plugin] copy for tag 0.4.0

[maven-release-plugin] copy for tag 0.3.0

[maven-release-plugin] copy for tag 0.2.1

[maven-release-plugin] copy for tag 0.2.0

[maven-release-plugin] copy for tag 0.1.2

[maven-release-plugin] copy for tag 0.1.1

Added CHANGELOG.md