Implemented the remaining test cases. Implemented 100%, secured 100%,
tested 75%. Final milestone reached.
Minor changes made to the business model - Add Training Pool to Employee
assigned to actor HR
Fourth milestone in progress - added unit tests for the implemented use
cases, and any missing unit tests related to crucial classes of the
project. Resolved or discarded all pending TODOs. Moved functional tests
to a separate source folder for convenience. Implemented 100%, secured
100%, tested 86%.