This commit fixes some issues regarding the `TuneableScheduledMutator`,
which had an edge case for drawing probabilities.
The user is supposed to provide a vector with probabilities that have to
add up to 1.0, but due to floating-point errors, the number can be
sligthly off.
If the sum ends up being slow, there's a chance that we draw a number
that is bigger than it (for example, 1.0), and that would not be present
in the cumulative distribution vectors (either for iterations or
mutations).
The issue is fixed by setting the last value of the cumulative
distribution to 1.0.
This commits adds some validations in the function that calculates the
cumulative distribution function, making sure that the numbers add up to
1, and that they are all between 0 and 1.
The API is now changed so the functions can now return an error instead
of crashing.
The commit also adds some tests, and fixes the `reset()` function.
174b852e0a