[maven-release-plugin] copy for tag 0.20.1

[maven-release-plugin] copy for tag 0.21.1

[maven-release-plugin] copy for tag 0.21.0

[maven-release-plugin] copy for tag 0.21.0-alpha3

[maven-release-plugin] copy for tag 0.21.0-alpha2

[maven-release-plugin] copy for tag 0.21.0-alpha1

[maven-release-plugin] copy for tag 0.20.0

[maven-release-plugin] copy for tag 0.19.0

[maven-release-plugin] copy for tag 0.19.0-alpha3

[maven-release-plugin] copy for tag 0.19.0-alpha2