load_json function missing in models.py
Section 33-code-decoupling-abstraction, exercise Add an Additional DataSource refers to function load_json in models. However, this function does not exist in any of the branches of python-intermediate-inflammation
This is the state of Thomas' original course content for section 3: https://github.com/ukaea-rse-training/python-intermediate-development
And this is the project repo that we use, which might differ slightly: https://github.com/ukaea-rse-training/python-intermediate-inflammation
Will be addressed as part of #408. This came about due to object oriented material being removed (along with this aspect), so needs to be added back in. Closing.