err was not checked in the .end()-methods.

from https://github.com/visionmedia/supertest:
"If you are using the .end() method .expect() assertions that fail will not throw - they will return the assertion as an error to the .end() callback. In order to fail the test case, you will need to rethrow or pass err to done(), as follows:"
callback was not invoked
Merge pull request #2 from m-unterberger/master

Bug fixes