Updates from using this as the JupyterLab basis

[blink1073]

This was created as part of jupyterlab/jupyterlab#3270. It uses some patterns from the ipython version.

• adds enhanced support for npm and auto-detection of yarn.
• adds support for ** glob patterns in data_files and package_data.
• adds functions to ensure the python version and get the package version.
• adds a convenience function to create a Command that calls a callback when run
• general cleanup

[blink1073]

cf https://github.com/vidartf/opinionated-widget-cookiecutter/pull/3 for another usage of the same file

[vidartf]

LGTM 👍