blacklist some pytests (#4502)

reaperhulk · alex · commit d2df398bcdcf · 2018-10-19T09:29:42.000-04:00
diff --git a/setup.py b/setup.py
@@ -54,7 +54,7 @@
         )
 
 test_requirements = [
-    "pytest>=3.6.0",
+    "pytest>=3.6.0,!=3.9.0,!=3.9.1",
     "pretend",
     "iso8601",
     "pytz",
