[tests] fix yaml load warning (#1522) (#1534)

Co-authored-by: Thomas Decaux <[email protected]>

Author: jmlrt

helpers/helpers.py

@@ -10,7 +10,7 @@ def helm_template(config):
         with open(temp.name, "w") as values:
             values.write(config)
         helm_cmd = "helm template release-name -f {0} ./".format(temp.name)
-        result = yaml.load_all(check_output(helm_cmd.split()))
+        result = yaml.load_all(check_output(helm_cmd.split()), Loader=yaml.FullLoader)
 
         results = {}
         for r in result: