RunNoseTestFocused fails if cursor is on the test function declaration

[tyewang]

Suppose you have the following test setup:

class TestA(...):
    def test_foo(self):
        ...
class TestB(...):
    def test_bar(self):
        ...

If the cursor is on the def test_foo line, RunNoseTestFocused will end up running TestA.test_bar, which doesn't exist.