Random process on RepeatedLineTracking algorithm is not reproducible

There is a random walk inside this algorithm, with an unparameterized seed which makes it less reproducible on each try:

https://gitlab.idiap.ch/bob/bob.bio.vein/blob/master/bob/bio/vein/extractors/RepeatedLineTracking.py#L99

It would be good to set a seed thorugh a parameter to the constructor.