Please make it a Java Module

[ptrd]

Can you make it a Java Module? The effort is minimal (see #4), and the benefit is large ;-).

I use siphash in a Gradle based open source project that uses Java Modules for modularization. Unfortunately, Gradle is not very friendly towards jars that are not Java Modules, i.e. it refuses automatic-modules that don't have the Automatic-Module-Name header set.
Long story short: I had to create my own version of siphash to make it a (proper) module and use that in my project. I rather not use this approach, therefore I hope you will accept my Pull Request or make it a Java Module otherwise.

Thanks!
Peter.