commented R16B03 in .travis.yml for now..

.travis.yml

@@ -1,6 +1,6 @@
 language: erlang
 otp_release:
-  - R16B03
+#  - R16B03 (not yet available on travis)
   - R16B02
   - R15B03
 #  - R14B04 (seems lists:concat/1 is broken on R14B04..)