- We should stop auto updating 3.6 now, so we can move on to
newer notebook packages - a new notebook version ought to fix
issues like https://github.com/2i2c-org/infrastructure/issues/1170
for example.
- No longer explicitly pin nbconvert, as whatever version notebook
brings in should be sufficient.
- Bump up ipywidgets and jupyterlab while we're at it.
- No longer pin jupyterhub-singleuser either, as that too works
properly with 3.7
use different .lock filename extension, following conda-lock precedent
Could also follow .txt in conda docs!
conda env create -p prefix -f lock.txt *should* work,
but fails with errors about name being required,
but also fails if name is given due to conflict with `-p`