created answerManager unit test
- service test folder added
Merge remote-tracking branch 'upstream/master'
answer manager service integration tests

- added integration test
- fixed optional parameters getAnswers method
- minor typo fix
validation tests updatet and added null checks
manually merged conflicts
Merge remote-tracking branch 'upstream/master'
Merge pull request #58 from geertvh/master

answer tests added, summaries fixed, validation tests fixed