Use Binder Jupyterlab

[kaedonkers]

I like the revamp of the courses a lot, great work!

Good to see Binder being used for the notebooks. I have a couple of suggestions of where you could go next for a better user interaction:

1. Use Jupyter Lab instead of Jupyter Notebooks on Binder
   It is easy to implement by changing the end of the Binder url from
   ...?filepath=path%to%notebook.ipynb to ...?urlpath=lab/tree/path/to/notebook.ipynb
   See this example from the Informatics Lab
   https://binder.pangeo.io/v2/gh/informatics-lab/itk-3dvis/master?urlpath=lab/tree/itk-3dvis.ipynb
   and guidance on some of the nuances in this repo
   https://github.com/binder-examples/jupyterlab

2. Use Pangeo Binder
   https://binder.pangeo.io is a Binder service from the Pangeo organisation on Google Cloud Services. It has more resources than the regular Binder deployment so might have a bit more grunt for Iris's data crunching requirements.