add a tox target to randomize tests
diff --git a/tox.ini b/tox.ini
index 4d4ac20..151b553 100644
--- a/tox.ini
+++ b/tox.ini
@@ -63,6 +63,13 @@
 commands =
     flake8 .
 
+[testenv:randomorder]
+deps =
+    {[testenv]deps}
+    pytest-random
+commands =
+    py.test --capture=no --strict --random {posargs}
+
 [flake8]
 exclude = .tox,*.egg
 select = E,W,F,N,I