"TypeError: 'module' object is not callable" when running with py.test under /test folder
===

I have a class `Foo` which lives in `Src/Projects/SomeProject/Foo.py`

I have a class `FooTest(unittest.TestCase)` which lives in: 

    Src/Projects/SomeProject/tests/FooTest.py

When I run it with pytest (I just type 'py.test' in Src to run all tests), I get:

     def setUp(self):
         self.foo = Foo()
         TypeError: 'module' object is not callable

(I have `from Foo import Foo` in `FooTest.py` and `Foo.py` is in `sys.path`. 

But when I run it with python: `python Src/Projects/SomeProject/tests/FooTest.py` everything works.)

Also, if I just move FooTest.py to `Src/Projects/SomeProject` then running with py.test suddenly works.

Any ideas?
