Merge pull request #54 from jorisvervuurt/master

Added integration tests for FeedbackService.
Merge pull request #55 from jorisvervuurt/master

Added integration tests for UserManager, bugfixes in FeedbackManager and UserManager.
userservice created
changed the class type of the managers to public
twitter client fixed
Twitter test client created
manual merge upstream/master
Merge pull request #56 from daanvc/master

usersevice created
Merge remote-tracking branch 'upstream/master'
Updated user service test to use IUserService.