Update pytest.ini

Author: mdmintz

pytest.ini

@@ -1,5 +1,17 @@
 [pytest]
+
 # Let console output be seen. Don't override the pytest plugin.
 addopts = --capture=no --ignore conftest.py -p no:cacheprovider
+
 # Ignore warnings such as DeprecationWarning and pytest.PytestUnknownMarkWarning
 filterwarnings = ignore::pytest.PytestWarning
+
+# Here are the pytest markers used in the example tests:
+# (pytest v4.5.0 and newer requires marker registration to prevent warnings.)
+# (Future versions of pytest may turn those marker warnings into errors.)
+markers =
+    marker1: custom marker
+    marker2: custom marker
+    marker3: custom marker
+    marker_test_suite: custom marker
+    expected_failure: custom marker