Update vendored pydot (1.4.2.dev0)

[davidlatwe]

Problem

On Windows, when the Python is running from a Conda envirnoment, and Graphviz is NOT installed by Conda, dot executable will not be found. Because pydot changed to look for dot.bat if Conda environment is detected.

Solution

This is a rare case, and maybe even won't happen in production. But I was doing some tests with my IDE that has set to use Conda as virtual environment provider, so.. to avoid all those confusion in the future, I propose to update pydot which they already have a fix for this problem.

The problem cause: pydot/pydot-ng#52 L413-L417
The issue in pydot : pydot/pydot#205
The fix they made: pydot/pydot#237

Other changes they have made should not be a problem for Rez to accept. Only 4 commits after last update.

[maxnbk]

disclaimer, I have not looked at the commits yet, but please be aware we had to make some updates to the vendored pydot not to break imports when using py3 and during rez install steps, so it would be good to verify that the new vendored pydot is compatible in the same ways.

[davidlatwe]

not to break imports when using py3 and during rez install steps

Hi, thanks to have a look. :)
And yep, checked that while I updating it.