corrected "penalty" name to "constraint violation" and introduced options for custom penalty functions

added opt course examples, and added gradient calculation of more than one output when using the wrapper

problems example elaborated. its noted however that make_notebooks is not working due to a bug in the drivers.ipynb

Witold Skrzypiński authored 5 years ago and Mikkel Friis-Møller committed 5 years ago

Inputs for calculate_devex and calculate_capex converted from lists to np arrays within the methods.