add notebook for FINOR webinar

[mattmilten]

I am unsure of how we want to publish this. It's copyrighted by FINOR. They did a Gurobi webinar and this is the supplementary material. https://www.gurobi.com/events/proven-techniques-for-solving-financial-problems-with-gurobi/ It used to be on their GitHub but is not accessible anymore.

• [x] clean up the requirements file (or remove it altogether?)
• [x] tell Marketing to point their link to this repo
• [x] add notebook to overview
• [x] get permission from FINOR for publication
• [x] update copyrights

[mattmilten]

We got the OK from FINOR to publish the code under our name. I will update the files accordingly.