Jupyter-packaging

* Fix skip_if_exists logic [58](https://github.com/jupyter/jupyter-packaging/pull/58) ([jtpio](https://github.com/jtpio))
* test for nested source folder [57](https://github.com/jupyter/jupyter-packaging/pull/57) ([vidartf](https://github.com/vidartf))

* allow trailing slashes in spec [56](https://github.com/jupyter/jupyter-packaging/pull/56) ([vidartf](https://github.com/vidartf))

* Add local testing instructions [55](https://github.com/jupyter/jupyter-packaging/pull/55) ([blink1073](https://github.com/blink1073))
* feat: add skip_if_exists command to skip when paths exists [54](https://github.com/jupyter/jupyter-packaging/pull/54) ([maartenbreddels](https://github.com/maartenbreddels))
* Allow --prefix to work [52](https://github.com/jupyter/jupyter-packaging/pull/52) ([dsblank](https://github.com/dsblank))

* Import sdist from distutils instead of setuptools [51](https://github.com/jupyter/jupyter-packaging/pull/51) ([jasongrout](https://github.com/jasongrout))

* Require the packaging package [49](https://github.com/jupyter/jupyter-packaging/pull/49) ([blink1073](https://github.com/blink1073))
* Switch to gh actions [48](https://github.com/jupyter/jupyter-packaging/pull/48) ([blink1073](https://github.com/blink1073))

* Allow files to be excluded [47](https://github.com/jupyter/jupyter-packaging/pull/47) ([blink1073](https://github.com/blink1073))