GUI not working on MacOS Big Sur 11.0.1

[Ian Brettell]

Hi,

I've installed the GUI-only version (`pip install 'idtrackerai[gui]') on my Mac, but it won't launch.

The first error was this:

```

ImportError: ('Unable to load OpenGL library', 'dlopen(OpenGL, 10): image not found', 'OpenGL', None)

```

Which I resolved by following this answer: https://stackoverflow.com/questions/63475461/unable-to-import-opengl-gl-in-python-on-macos

But now it crashes with the following error:

```

AttributeError: 'QOpenGLFunctions_4_1_Core' object has no attribute 'glMatrixMode'

```

I'd appreciate your assistance.

Best,

Ian