Let's implement some tests :) #71

Hey, everybody

I was thinking it would be great if we can add some tests to validate our models, in addition to a CI/CD pipeline that helps to ensure future modifications won't break anything.

I'm not sure how to implement this in all the different languages here. Should we create a tests folder and replicate the root structure inside? Should we add tests to each root folder with a special extension as .spec or .test? Each test suit should run by its own or we should create a make file to run all of them at once?