Merge pull request jupyterlab#98 from ian-r-rose/jupyterlab-2.0

Jupyterlab 2.0

Publish v1.0.0-pre.1

Release v0.10.0.

Merge pull request jupyterlab#67 from ian-r-rose/0.34

Updates for JupyterLab 0.34

Merge pull request jupyterlab#60 from ian-r-rose/jlab0.33

Updates for 0.33