Fix running tests with PyQt 5.11

This was causing the test runner to crash.

tests/conftest.py

@@ -6,6 +6,8 @@
 import unittest.mock
 import pytest
 
+import Arcus #Prevents error: "PyCapsule_GetPointer called with incorrect name" with conflicting SIP configurations between Arcus and PyQt: Import Arcus and Savitar first!
+import Savitar
 from UM.Qt.QtApplication import QtApplication #QtApplication import is required, even though it isn't used.
 from cura.CuraApplication import CuraApplication
 from cura.MachineActionManager import MachineActionManager