Strict pytest

setup.cfg

@@ -42,6 +42,12 @@ known_third_party = click,does_not_exist,gunicorn,h11,httptools,pytest,requests,
 
 [tool:pytest]
 addopts = -rxXs
+  --strict-config
+  --strict-markers
+xfail_strict=True
+filterwarnings=
+    # Turn warnings that aren't filtered into exceptions
+    error
 
 [coverage:run]
 omit = venv/*