Add support for OULAD

[anupamamurthi]

https://analyse.kmi.open.ac.uk/open_dataset

[nrkarthikeyan]

Tasks:

• [ ] Ensure the license permits open source use.
• [ ] Verify that this dataset is appropriate for fairness tasks and subset it accordingly (removing un-necessary columns etc.).
• [ ] Ensure we have instance level records with protected attributes and outcomes.
• [ ] First create sklearn-compatible dataset (dataframe) and an appropriate "classic" dataset (second priority).
• [ ] Create a simple notebook where the dataset is consumed and simple fairness measures and computed at least.