fix(nose): Comment out detailed-errors to workaround a testtools+nose bug

Setting "detailed-errors=1" in setup.cfg causes a bug in testtools to
manifest.

Trigger: self.assertX(condition), where condition == False.

In "testtools/testresult/real.py" the traceback is set to
None in _details_to_exc_info(), but the inspect_traceback()
method in nose/inspector.py requires a traceback-like object.

Change-Id: Ia95fd2176ea0ccc984623b53b3536f995c6db5bb
Merge "fix(nose): Comment out detailed-errors to workaround a testtools+nose bug"