maven 3.8

prepare for release

[maven-release-plugin] copy for tag v7.1.0

[maven-release-plugin] copy for tag v7.0.1

[maven-release-plugin] copy for tag v7.0.0

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

[maven-release-plugin] copy for tag v6.1.0

[maven-release-plugin] copy for tag v6.0.0

[maven-release-plugin] copy for tag v5.2.0

[maven-release-plugin] copy for tag v5.1.0