Fix error when instantiating the IntegrationCache

conftest.py

@@ -58,6 +58,7 @@ class IntegrationCache():
         # Use the same sources every time
         self.sources = os.path.join(cache, 'sources')
 
+        os.makedirs(cache, exist_ok=True)
         # Create a temp directory for the duration of the test for
         # the artifacts directory
         try: