Prepare release zt-zip-1.6

[maven-release-plugin] copy for tag zt-zip-1.5

[maven-release-plugin] copy for tag zt-zip-1.4

[maven-release-plugin] copy for tag zt-zip-1.3

[maven-release-plugin] copy for tag zt-zip-1.2

[maven-release-plugin] copy for tag zt-zip-1.1

[maven-release-plugin] copy for tag zt-zip-1.0