[ATMOSPHERE-590][stable/zed] Add support for nfs_shares_config (#2141)

This is an automated cherry-pick of #2121
/assign larainema
Depends-On: #2149
diff --git a/tox.ini b/tox.ini
index ff3459b..34519eb 100644
--- a/tox.ini
+++ b/tox.ini
@@ -113,3 +113,7 @@
   rjsonnet
 commands =
   python3 {toxinidir}/hack/promtool-test.py
+
+[testenv:helm-unittest]
+commands =
+  python3 {toxinidir}/hack/helm-unittest.py