Merge pull request jupyterlab#44 from ian-r-rose/jlab0.32

Updates for JupyterLab v0.32

Merge pull request jupyterlab#31 from ian-r-rose/jlab_0.31

Updates for JupyterLab 0.31rc2

Merge pull request jupyterlab#24 from ian-r-rose/jlab_0.30

Updates for JupyterLab 0.30