Added a version number for pitest
Moved the creation of player's UI part outside, stub it in tests
Add todo about minor duplication.
Moved the creation of game's UI part outside, use it in the tests
Adopted the ui test using a stub to verify that the message has been called
Added TODO to remember to increase test coverage
Moved test for printing to its own UI test class; remove duplication of player and mocked UI creation
Renamed PlayerUI to PlayerUi
Renamed GameUI to GameUi