add clean instructions on how to run the notebooks in JuliaBox

[bertdv]

• students shoudl be able to run teh notebooks interactively in JuliaBox.
• We should also point students to a site where the instrutions are to let them install julia on their own laptops. I dont think we want to provide an introductory class on julia. The code is very readable so interested students can study Julia by themselves.
• I think we should add IJulia to the line map(Pkg.add, ["Cubature", "DataFrames", "Distributions", "Interact", "PyPlot"]) in the README (just for students who work with julia on their own laptops, right? `

[bertdv]

I think this is done, right? At least I see an updated README, thx. So I close the issue