Fix for rich comparison and add test for vec3 file

As __cmp__ no longer in Python 3 need to use functools.total_ordering which is in 2.7 and 3.*
  https://docs.python.org/2/library/functools.html#functools.total_ordering
  https://docs.python.org/3/library/functools.html#functools.total_ordering
  Define __eq__ and __lt__ and others are created automatically

Add unittest style for file vec3.py
This would be a very confusing implementation of `__lt__` because `(0,1) < (1,0) && (1,0) < (0,1)` so it's not even a partial ordering (violates antisymmetry)

I think you want `and` not `or`, c.f. https://en.wikipedia.org/wiki/Ordered_vector_space