Add environment file for US cloud

Change-Id: I9f230bb71a367cbe1c759bb3d0f58e734ec77a80
diff --git a/tcp_tests/managers/envmanager_heat.py b/tcp_tests/managers/envmanager_heat.py
index 8d1e50e..ca1f41d 100644
--- a/tcp_tests/managers/envmanager_heat.py
+++ b/tcp_tests/managers/envmanager_heat.py
@@ -142,7 +142,10 @@
         for stack in stacks:
             if stack_id == stack.id:
                 if stack.parent:
-                    return self.__get_stack_parent(stack.parent, stacks)
+                    try:
+                        return self.__get_stack_parent(stack.parent, stacks)
+                    except Exception:
+                        return stack.id
                 else:
                     return stack.id
         raise Exception("stack with ID {} not found!".format(stack_id))