Update cloudpickle to 0.5.3

[pyup-bot]

This PR updates cloudpickle from 0.5.2 to 0.5.3.

Changelog

0.5.3

=====
- Fixed a crash in Python 2 when serializing non-hashable instancemethods of built-in
types ([issue 144](https://github.com/cloudpipe/cloudpickle/issues/144)).

- itertools objects can also pickled
([PR 156](https://github.com/cloudpipe/cloudpickle/pull/156)).

- `logging.RootLogger` can be also pickled
([PR 160](https://github.com/cloudpipe/cloudpickle/pull/160)).

Links

• PyPI: https://pypi.org/project/cloudpickle
• Changelog: https://pyup.io/changelogs/cloudpickle/
• Repo: https://github.com/cloudpipe/cloudpickle

[pyup-bot]

Closing this in favor of #295