glmtools and Big Sur on Macs

[jaymtee]

To get glmtools and jupyter notebook to play well together I needed to do the following:

1. edit the environment.yml file to require python=3.8
2. change to glmval env
3. (as mentioned in the readme) conda install -c conda-forge nb_conda_kernels
4. (as mentioned in the readme) conda install -c conda-forge ipywidgets
5. conda install -c conda-forge matplotlib
6. use the following on mac: (glmval)$ pip install e .