implement tests

[lucasosouza]

Not clear yet where to start testing and how to test
Just need to ensure that small changes won't break algorithms

Maybe intead of just unit testing, which will track bugs in code, can do a sort of functional testing
comparing algorithms to some baseline I have saved, to see if the changes introduced increase/reduce wall clock time or increase/reduce performance of the algorithm

that would be more interesting than unit tests, since code issues can be easily debugged, while algorithm issues are hard to identify and hard to fix, requires a lot of manual debugging