add conftest file

tests/conftest.py

@@ -0,0 +1,14 @@
+import pytest
+
+def pytest_addoption(parser):
+    parser.addoption(
+        "--runslow", action="store_true", default=False, help="Run slow tests"
+    )
+
+def pytest_collection_modifyitems(config, items):
+    if not config.getoption("--runslow"):
+        # Skip slow tests unless --runslow is specified
+        skip_slow = pytest.mark.skip(reason="Need --runslow option to run")
+        for item in items:
+            if "slow" in item.keywords:
+                item.add_marker(skip_slow)