cadquery and cadquery-ocp Dependencies Will Not Install Through Addon Manager

I keep getting an error when trying to install this workbench through the addon manager, although the workbench will still install. I have tried several things without success. I have posted a question about it on the FreeCAD forum [here](https://forum.freecad.org/viewtopic.php?t=93604). Hopefully I will get an answer.

In the meantime, I have added manual installation options in the `CadQuery` menu, documented [here](https://github.com/CadQuery/cadquery-freecad-workbench/blob/master/docs/installation.md#install-cadquery-stable).