Comment 2 for bug 1922975

Thank you so much, Jeff! Works well for me on python 3, so I've signed off on it.

It looks like the recommendation is to specify the major python version in the shebang line if it only works on one python3 (https://docs.python.org/3/using/unix.html#miscellaneous).

It seemed simplest to just provide your python3 version of the scripts, and have packagers and translators use python3 for their work, regardless of which OS they use. So I've added another commit that installs python3 versions of all those dependencies, and specifies python3 in the shebang lines.

The signoff and follow-up commit are available at user/sandbergja/lp1922975_python3