[maven-release-plugin] copy for tag v6.8.1

[maven-release-plugin] copy for tag v6.8.0

[maven-release-plugin] copy for tag v6.7.0

[maven-release-plugin] copy for tag v6.5.0

[maven-release-plugin] copy for tag v6.4.3

[maven-release-plugin] copy for tag v6.4.2

[maven-release-plugin] copy for tag v6.4.1

[maven-release-plugin] copy for tag v6.4.0

[maven-release-plugin] copy for tag v6.3.0

[maven-release-plugin] copy for tag v6.2.0