====================
- `Cluster.remove_zone` now raises `ValueError` on attempt to remove a
non-existent zone.
- `Cluster.remove_node` and `RendezvousHash.remove_node` now raise
`ValueError` on attempt to remove a non-existent node.
- Support for custom hash functions retracted for 1.0.0 milestone.
- `murmur_seed` keyword argument renamed to `seed` for `Cluster` and
`RendezvousHash` `__init__` methods.