Update jupyterlab to 0.32.1

[pyup-bot]

This PR updates jupyterlab from 0.31.2 to 0.32.1.

Changelog

0.32.0

Apr 16, 2018
This is the second in the JupyterLab Beta series of releases. It contains many enhancements, bugfixes, and  refinements, including:

* Better handling of a corrupted or invalid state database ([3619](https://github.com/jupyterlab/jupyterlab/issues/3619), [3622](https://github.com/jupyterlab/jupyterlab/issues/3622), [3687](https://github.com/jupyterlab/jupyterlab/issues/3687), [4114](https://github.com/jupyterlab/jupyterlab/issues/4114)).
* Fixing file dirty status indicator ([3652](https://github.com/jupyterlab/jupyterlab/issues/3652)).
* New option for whether to autosave documents ([3734](https://github.com/jupyterlab/jupyterlab/issues/3734)).
* More commands in the notebook context menu ([3770](https://github.com/jupyterlab/jupyterlab/issues/3770), [3909](https://github.com/jupyterlab/jupyterlab/issues/3909))
* Defensively checking for completion metadata from kernels ([3888](https://github.com/jupyterlab/jupyterlab/issues/3888))
* New "Shutdown all" button  in the Running panel ([3764](https://github.com/jupyterlab/jupyterlab/issues/3764))
* Performance improvements wherein non-focused documents poll the server less ([3931](https://github.com/jupyterlab/jupyterlab/issues/3931))
* Changing the keyboard shortcut for singled-document-mode to something less easy to trigger ([3889](https://github.com/jupyterlab/jupyterlab/issues/3889))
* Performance improvements for rendering text streams, especially around progress bars ([4045](https://github.com/jupyterlab/jupyterlab/issues/4045)).
* Canceling a "Restart Kernel" now functions correctly ([3703](https://github.com/jupyterlab/jupyterlab/issues/3703)).
* Defer loading file contents until after the application has been restored ([4087](https://github.com/jupyterlab/jupyterlab/issues/4087)).
* Ability to rotate, flip, and invert images in the image viewer ([4000](https://github.com/jupyterlab/jupyterlab/issues/4000))
* Major performance improvements for large CSV viewing ([3997](https://github.com/jupyterlab/jupyterlab/issues/3997)).
* Always show the context menu in the file browser, even for an empty directory ([4264](https://github.com/jupyterlab/jupyterlab/issues/4264)).
* Handle asynchronous comm messages in the services library more correctly (Note: this means `jupyterlab/services` is now at version 2.0!) ([[4115](https://github.com/jupyterlab/jupyterlab/issues/4115)](https://github.com/jupyterlab/jupyterlab/pull/4115)).
* Display the kernel banner in the console when a kernel is restarted to mark the restart ([[3663](https://github.com/jupyterlab/jupyterlab/issues/3663)](https://github.com/jupyterlab/jupyterlab/pull/3663)).
* Many tweaks to the UI, as well as better error handling.

Links

• PyPI: https://pypi.org/project/jupyterlab
• Changelog: https://pyup.io/changelogs/jupyterlab/
• Homepage: http://jupyter.org

[pyup-bot]

Closing this in favor of #268