Add tests, add RTD, add PyPI release

[barseghyanartur]

Hey, Douwe. I hope you're doing well! I accidentally came across this package (thanks to GitHub). A couple of remarks (if you want this to be used).

• Add tests
• Add RTD
• Add PyPI release
• Add license

[douwevandermeij]

Hi Artur, I'm fine thanks! Hope you too!
Thanks for the feedback, good points, I'll consider ;)
You use it?