Update jupyter-client to 6.1.0

[pyup-bot]

This PR updates jupyter-client from 5.3.4 to 6.1.0.

Changelog

6.1.0

=====

This release includes support for asyncio patterns! Downstream tools should soon have releases to additionally support async patterns.

- AsyncKernelManager and AsyncMultiKernelManager are now available for async jupyter_client interactions (:ghpull:`528`, :ghpull:`529`)
- Removed unused sphinx dependency (:ghpull:`518`, :ghpull:`518`).
- Added install instructions for pip to documentation (:ghpull:`521`)
- Improved docs around version protocol and messaging (:ghpull:`522`, :ghpull:`526`)

6.0.0

=====

The git history had to be reworked heavily in merging 5.x and master, so a link to all the changes at once in github had been left out as it's just confusing.

An exciting change in this release is some async support (huge thanks to davidbrochart for doing most of the work)! See linked PR below for more details, we're working on integrating this into nbclient as well in the near future.

New Features:

- Added async API (:ghpull:`506`)

Changes:

- Python 3.8 testing and support added (:ghpull:`509`)
- Session.msg_id optimization (:ghpull:`493`)
- Only cache ports if the cache_ports flag is set to True (:ghpull:`492`)
- Removed direct dependency on pywin32 as this is now in jupyter core (:ghpull:`489`)

Fixes:

- Prevent two kernels to have the same ports (:ghpull:`490`)

Docs:

- Document the handling of error in do_execute (:ghpull:`500`)

Breaking changes:

- Dropped support for Python 2.7!

Links

• PyPI: https://pypi.org/project/jupyter-client
• Changelog: https://pyup.io/changelogs/jupyter-client/
• Homepage: https://jupyter.org

[pyup-bot]

Closing this in favor of #167