Switching form frozenset to list for outcomes in bin

The book wanted a frozenset, but that implies the objects are
hashable. Python custom classes are hashable until you overwrite their
__eq__ method, which we were asked to do. They can only again be
hashable if eq is only true between two objects that share the same
hash. But this is not what we were asked to make eq do. However, a list
accomplishes the same thing, and does not require hashable objects,
instead comparing objects by eq (giving us the desired behavior). This
does make __contains__ on Bin to be O(n) instead of O(1), but unless we
re-write the hash function, we can't use hashes AND treat two different
objects as equal if their name matches.

By the wall, all tests passing now.