Fix up the PCX2 test, so it will work even though PCSX2 is not there.

This isn't as fancy as MagicMock, but I need to stub out a couple of functions in the runner being testing, so MagicMock doesn't work.

tests/runners/test_pcsx2.py

@@ -8,6 +8,8 @@ class TestPCSX2Runner(unittest.TestCase):
 
     def setUp(self):
         self.runner = pcsx2()
+        self.runner.get_executable = lambda: "pcsx2"
+        self.runner.get_command = lambda: ["pcsx2"]
 
     @patch('os.path.isfile')
     def test_play_iso_does_not_exist(self, mock_isfile):