Have written PlayerImpl class, currently doesn't pass getName test.
All tests in PlayerTest now pass.

Added comments to PlayerTest, and re-arranged initialisation of
testName1 & 2 so that it is now initialised before it is used in the
construction of the new PlayerImpl objects.
Added first tests for Question(Impl) class
Added comments for constructor
Changed comments in Question interface
Added another test to PlayerTest
Change the code to initialise playerID server side

Realised the Player ID should be initialised server side
Added test for constructor & get answers methods
Corrected tests and comments
QuestionImpl now passes all tests
Added test for isCorrect method
Added test to ensure answer comparison is not case sensitive.
Changed test to expect null pointer exception as boolean cannot be null.
ContactImpl now passes all tests!!