Travis: also test on 32-bit Linux

diff --git a/RelNotes b/RelNotes
index f8e49a5070afc21fbd3db9320841300fe93c570f..7f250ddc2efa8f8d3a46ccecb4d810695387798a 120000 (symlink)
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes-1.6.4.txt
\ No newline at end of file
+Documentation/RelNotes/2.11.1.txt
\ No newline at end of file