Fix homogeneous sequence boundary

[hwwhww]

What was wrong?

Address issue #116

How was it fixed?

1. Remove HomogeneousProperCompositeSedes.__init_()
2. Update vector types' (Vector and Bitvector) __init__() with illegal condition max_length < 1.
3. Add list types' (List and Bitlist) __init__() with illegal condition max_length < 0.
4. Use ValueError for these exceptions.
5. Add tests: test_homogeneous_sequence_length_boundary and test_bitfield_length_boundary

Cute Animal Picture

/cc @booleanfunction @saltiniroberto

[saltiniroberto]

Why the change here? Given that we are dealing with int, <= 0 is equivalent to < 1

[hwwhww]

Yes, it's equivalent. I wanted to make it more clear and follow the error message more tightly.