Notebooks: makes notebooks deterministic and prints output of asserts

[fabianandresgrob]

PR for #842 and #843

[nickfraser]

Can you test the following:

• Running (run-all from the top) these notebooks multiple times will produce the same output
• Running them from the commandline with in-place updating will produce the same output as above
• Running from the commandline on a new machine will also produce the same output

I have a small script to run the notebooks like so:

#!/bin/bash
# source: https://mljar.com/blog/run-jupyter-notebook-command-line/
for f in *.ipynb; do
    cp $f $f.orig
    jupyter nbconvert --execute --allow-errors --to notebook --inplace $f
    echo nbdiff-web -b /dev/null $f.orig $f
done

My goal is that when you compare with ndiff-web and a manual notebook run through the browser, you should get the same output (ignore warnings and such). This will make it easier to verify that the notebooks work in future.

[fabianandresgrob]

Checked using that script, everything looks good. Only minor things differ like kernel id. I added one more torch.manual_seed() to the ONNX export.

[Giuseppe5]

When doing multiple runs to compare, restart the kernels, just to be sure

[Giuseppe5]

Rebase please

[nickfraser]

LGTM!