Add tests for submodule sync --recursive

diff --git a/RelNotes b/RelNotes
index 53d76d1a47e0750b0d8b14287ff3d923ca55b438..2484b38bbbae654684f65a874653487439f0df2f 120000 (symlink)
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes/1.7.12.1.txt
\ No newline at end of file
+Documentation/RelNotes/1.8.0.txt
\ No newline at end of file