Add test for question MatrixTable\Likert. Added MissingParameterException for missing parameters in the QuestionFactory.
Add MissingParameterException for MultipleChoice\SingleAnswer and MultipleChoice\MultipleAnswer.
Removed single used variable.
Renamed repository property.
Moved object creation from InMemoryRepository to AnswerFactory.
Add test for InMemoryResponseRepository.
Improved readability.
Moved fixtures from InMemorySurveyRepository to tests.
Changed test method names to be more meaningful.
Removed application service tests. First the whole domain need to be covered with tests.