Travis: also test on 32-bit Linux

diff --git a/RelNotes b/RelNotes
index 3da01a5622c0b6c581a701dbb5421fb84e87df80..7f250ddc2efa8f8d3a46ccecb4d810695387798a 120000 (symlink)
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes-1.7.2.txt
\ No newline at end of file
+Documentation/RelNotes/2.11.1.txt
\ No newline at end of file