Port Script to Python3

[alpako]

Hello Thomas,

I spend some time to port this script to python 3.

Kind Regards

[thomai]

It seems like you fixed some PEP8 issues as well. Thank you very much for the changes!

I have to check the Python 2 compatibility before merging your changes. That'll take some time since I am working on other projects at the same time.

[ethan-mt]

@alpako please also update requirement.txt as it relies on Jinja2 package.

[bhaskoro-muthohar]

any update on this @thomai ?