bump Ubuntu to test on 3.9
@@ -97,7 +97,7 @@ jobs:
# https://github.com/executablebooks/jupyter-book/issues/906 is fixed.
# See https://jupyterbook.org/advanced/advanced.html#working-on-windows
- os: 'ubuntu'
- python-version: 3.8
+ python-version: 3.9
- os: 'windows'
python-version: 3.7
- os: 'macos'
