Bug 1370279 - Prevent conflicts with jenkins pytest configuration

This fixes the `ConftestImportFailure` exception seen when trying
to run pytest in Vagrant after bug 1286686 landed.

setup.cfg

@@ -28,6 +28,7 @@ line_length = 140
 known_first_party = tests
 
 [tool:pytest]
+norecursedirs = jenkins
 DJANGO_SETTINGS_MODULE=tests.settings
 markers =
     slow: mark a test as slow.