Jupyter hangs for nested direct transformations, only in the Seamless Docker image

[sjdv1982]

As revealed by the imperative-nested-jupyter.sh test.
In the conda environment, everything works fine.
Probably an outdated/bugged Jupyter and/or Python version in the base Docker image jupyter/notebook-base
For 0.14 release, bump Python version and jupyter/notebook-base to current versions.

[sjdv1982]

To look into again, since nesting was previously bugged in the Docker image

[sjdv1982]

Punt to 0.15 release