Add Jest and Unit Testing to JS2-3 Coursework

[ChrisOwen101]

Which module(s) and week(s) does this change effect? Module(s): JS2 Week(s): 3

What is the work that needs to be done?

Adding Jest Unit Testing to JS2-3 is the next step to automating marking and teaching our students about unit testing

https://github.com/CodeYourFuture/JavaScript-Core-2-Coursework-Week3

• [x] Add unit testing for the Exericses
• [x] Add unit testing for the To Do

The Bike Project can be safely skipped

Who need to know about this?

@CodeYourFuture/syllabus-team

[SallyMcGrath]

#289

[40thieves]

Linking it up: https://github.com/CodeYourFuture/JavaScript-Core-2-Coursework-Week3/pull/77 (I think this is the right one)