Add a newline to serialization results

Otherwise editing the output in an editor
is likely to make the data not match anymore,
since most editors will add a final newline.

Update all tests

1 files changed, 1 insertions, 1 deletions

diff --git a/tests/layouts/valid-12.layout b/tests/layouts/valid-12.layout
index b7ee6ddf..59451e08 100644
--- a/tests/layouts/valid-12.layout
+++ b/tests/layouts/valid-12.layout
@@ -785,4 +785,4 @@
       }
     ]
   }
-}
\ No newline at end of file
+}