Add tests

[caranha]

• [ ] Condition checks for variation operators (is everyone between 0 and 1? is the output a matrix of the right size? Is the behavior correct depending on parameters?
• [ ] Value checks for variation operatos (use fixed seeds, and some fixed examples)
• [ ] Condition checks for repair operators (is everyone between 0 and 1? is the output a matrix of the right size?)
• [ ] Value checks for repair operators (to verify they don't change parameters where not necessary)