Version 0.6

In this major update:

• @dataclass has received a new option, meta, allowing you to specify a custom metaclass
• __eq__ now compares the types of its arguments
• dataclasses' decorator options order and unsafe_hash have finally been implemented
• A custom __call__ is now only used when required
• The behaviour of fields() now matches the version from dataclasses
  • A new function, values() implements its old behaviour