IOPub issue from Jupyter >=5

[charlesfrye]

In the conversion from 4 to 5, Jupyter added a "feature" that halts data transmission from the kenrel to the client if it exceeds a certain threshold. This was intended to prevent massive text dumps to stdout or stderr, but it sometimes triggers when rapidly passing visualizations from the kernel to the notebook -- e.g. when making a "poor man's animation" by repeatedly calling canvas.draw on pyplot figures.

Simply filtering warnings doesn't work, since this is coming from Jupyter itself. The fix is to increase the threshold, but this requires reconfiguration of Jupyter, which I'd like to avoid, for the students' sake. I've reduced the load of some animations in Lab 08 A to prevent this, but I worry this might also trigger for other plots. Will need to be vigilant when creating student versions to see if this crops up elsewhere. Was supposed to be fixed in 5.1, but that doesn't appear to be the case 😢 .