Tests refactoring for ci

Function setUpPackage() from tests/__init__.py was modified: ostf-server
setup was added as child process via subprocess.Process() construction
so that now both unit and functional tests can be run without any pre
setup of fake ostf-server nor nailgunmimic because these actions are
managed now by nose.

Change-Id: Icc6972d1aa413321a89c924cda3b9cc9ae9cb4ee