SEBA-447 Check for closed db connections;
Remove dependency on django-rest-framework's exceptions

Change-Id: I440c459f1a65321e25d4f7794a24a9a4d92dbb00
diff --git a/tox.ini b/tox.ini
index a8ce26b..084a487 100644
--- a/tox.ini
+++ b/tox.ini
@@ -29,6 +29,7 @@
   nose2
   flake8
   pyfakefs
+  grpcio==1.19.0
 
 commands =
   nose2 -c tox.ini --verbose --junit-xml