Release 2.6.0

Signed-off-by: Chris Narkiewicz <hello@ezaquarii.com>

[maven-release-plugin] copy for tag stateless4j-2.5.0

[maven-release-plugin] copy for tag stateless4j-2.4.2

[maven-release-plugin] copy for tag stateless4j-2.4.1

[maven-release-plugin] copy for tag stateless4j-2.4.0

[maven-release-plugin] copy for tag stateless4j-2.3.0

[maven-release-plugin] copy for tag stateless4j-2.2.0

[maven-release-plugin] copy for tag stateless4j-2.1.0

[maven-release-plugin] copy for tag stateless4j-2.0.1

[maven-release-plugin] copy for tag stateless4j-2.0.0