Clean up notebooks

[bouweandela]

As a Remote sensing expert user of satsense
I would like to Have an example notebook showing how to use satsense
because I can use this as a starting point for my own research.

Most notebooks are outdated. Update or remove once we have a more stable API.

This notebook is most informative and relatively up to date:
satsense/notebooks/demo_notebooks/Classification/Simple Example.ipynb

[bouweandela]

Related #30

[bouweandela]

Got started on updating 'notebooks/demo_notebooks/Classification/Simple Example.ipynb' in the notebooks branch.

[bpmweel]

done.