Adding Hitachi support (with help of @hille721)

Changelog

• Adding support of Hitachi WWN

Python3 bump version

This package supports only Python version >3.6 now.

Fixing a bug with DMX decoding S/N feature (thanks to Ryan for reporting this bug)

## Changelog

• Fixing a bug with DMX decoding S/N feature (thanks to Ryan for reporting this bug)

Minor release with code cleaning and refactoring

Upload to PyPi done

First version usable in production

v0.5

First commit for the project 'devicewwn' (version 0.5)