converter to older python versions

[supernlogn]

I made a tool to convert all f-strings inside the vod-converter to older python strings
https://github.com/supernlogn/f-string-deconverter

So the project can be compatible to older python3 versions.

[krosaen]

Thanks! I will consider applying this and just making this project python3.5+ compatible. The fstrings are nice, but perhaps not worth the hassle given 3.5 is a pretty common default python3 install.

[krosaen]

In fact, if you want to open a pull request, I'd be happy to merge and go with 3.5 compatible code