[ATMOSPHERE-527] [stable/zed] Improve NeutronNetworkOutOfIPs alarm (#2064)

This is an automated cherry-pick of #2063
/assign larainema
diff --git a/tox.ini b/tox.ini
index bed67e1..ff3459b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -105,3 +105,11 @@
   bash
 commands =
   bash {toxinidir}/build/build-manila-image.sh
+
+[testenv:promtool-test]
+skip_install = true
+deps =
+  PyYAML
+  rjsonnet
+commands =
+  python3 {toxinidir}/hack/promtool-test.py