feat: support for jupyterlab

[zacharyrs]

Added support for jupyter lab.

• uses prebuilt js that can be distributed in python package
• swaps jquery ui to use version managed by the jquery ui team
• updates @jupyterlab-widgets/base to support newer versions (for jlab3)
• slightly tidied (?) the setup.py script

It's been a little while since I touched js stuff, so please forgive any naive mistakes!

Installs happily via pip install ., and works with my jupyter setup:

IPython          : 7.16.3
ipykernel        : 5.3.4
ipywidgets       : 7.6.5
jupyter_client   : 7.1.2
jupyter_core     : 4.9.1
jupyter_server   : 1.13.4
jupyterlab       : 3.2.8
nbclient         : 0.5.10
nbconvert        : 5.6.1
nbformat         : 5.1.3
notebook         : 6.4.8
qtconsole        : 5.2.2
traitlets        : 5.1.1

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

Fixes #55.

[krlawrence]

Thanks for the PR @zacharyrs - please give us a day or so to look it over. We very much appreciate contributions such as yours.

[michaelnchin]

Thank you very much for this PR, @zacharyrs!

I took some time to look over the changes made and test them out, and everything looks good. The widgets are working great in the latest build of JupyterLabs 3.x on my local setup. We had some initial concerns that such an upgrade could affect functionality on classic Jupyter Notebook, but the new build appears to be fully backwards-compatible with our current installation process.

This is an excellent first step towards JupyterLab support in this package; thank you again for your efforts.

[zacharyrs]

@michaelnchin Thanks!

Glad it's going through - I made sure I left the classic extension build as is, just added/improved the lab extension.
The one thing I'm not 100% sure about is widening the version ranges for @jupyterlab-widgets/base, but that seems to be behaving as expected.

Looking forward to seeing a new version published!

Cheers

[robipresotto]

Maybe a regression but graphs still not rendering on jupiterlab