Just force old pytester behaviour

DRMacIver · DRMacIver · commit ffa866a96fee · 2015-09-21T11:28:10.000+01:00
diff --git a/tox.ini b/tox.ini
@@ -83,4 +83,4 @@ commands =
   bash scripts/lint.sh
 
 [pytest]
-addopts=--strict --tb=short -vv
+addopts=--strict --tb=short -vv -p pytester --runpytest=subprocess
