Add warning filter

Author: TJ Bruno

test/__init__.py

@@ -1 +1,8 @@
 #!/usr/bin/env python
+
+import pytest
+
+# Ignore exceptions being raised as a result of BusABC.__del__
+pytestmark = pytest.mark.filterwarnings(
+    "ignore::pytest.PytestUnraisableExceptionWarning"
+)