v.1.2.7

Algorithm updates

added RPNI, a passive deterministic automata learning algorithm for DFAs, Moore, and Mealy machines
non-deterministic learning does no longer rely on all weather assumption (table shrinking and dynamic observation table update)

Features updates

following functions added to all model types
    mode.save()
    model.visualize()
    model.make_input_complete()
refactor file handler