Notebook Meta schema is occasionally replaced with empty object

[Nicholas Bollweg]

Description

Notebook metadata editor sometimes replaces schema value with {}

Reproduce

1. Open examples/Starter Notebook.ipynb
2. Click on in the notebook toolbar
3. Scroll down to Schema
4. See value is {}

Expected behavior

Value should be a required field called name.

Context

• Operating System and version: Ubuntu Linux 19.10
• Browser and version: Chromium 79
• JupyterLab version: 1.2.4
• jupyter-starters version: 0.2.0a0
• @deathbeds/jupyterlab-starters version: 0.2.0a0

[Nicholas Bollweg]

Closed by #21