Parsing fails when CurrentCulture uses comma as decimal separator

[hansmbakker]

I believe that CultureInfo.InvariantCulture is not enforced when parsing (number) values, and therefore various unit tests fail on my system.

[BennyBread]

just stumbled upon this repo. I made a fork and also noticed this error.
I have fixed it in my fork: https://github.com/BennyBread/GCodeNet