Tests

[amitchellunicef]

Add jest tests across the repo

Post-Merge Steps:

• Run yarn to update the dev dependencies necessary for the tests.
• Before running the tests, execute yarn clean and yarn compile
• To execute the tests, run yarn test

Functionality Change:

• The in app encyclopaedia search bar now compares the query string against article titles, not just their content

Other changes

• I have updated the deploy:k8s script to run the tests before deploying
• Some small changes to the prediction engine which should not affect its functionality