Make jupyterlab depend on an explicit version of jupyter-js-widgets.
Make jupyterlab depend on an explicit version of jupyter-js-widgets.

If another package depends on jupyterlab_widgets, it will need to pull down an explicit jupyter-js-widgets dependency version, not a relative path to jupyter-js-widgets.
ipython/ipywidgets,jupyter-widgets/ipywidgets,SylvainCorlay/ipywidgets,SylvainCorlay/ipywidgets,SylvainCorlay/ipywidgets,ipython/ipywidgets,jupyter-widgets/ipywidgets,cornhundred/ipywidgets,cornhundred/ipywidgets,cornhundred/ipywidgets,cornhundred/ipywidgets,ipython/ipywidgets,jupyter-widgets/ipywidgets,SylvainCorlay/ipywidgets,ipython/ipywidgets,jupyter-widgets/ipywidgets,cornhundred/ipywidgets,ipython/ipywidgets