Created RandomProbDist class to handle creation of a uniform random distribution for initial guesses. In order to comply with existing code structure, especially in MutableProbDist class, the self._probs variable in RandomProbDist is necessarily a dictionary of random values. Numpy was not previously imported in probability.py, so used random module instead. Should tackle most of #373
all prob matrices (_priors, _transitions, _outputs) are randomly init. Tested, should fix #373