travis.yml: use clang-4.0 for asan32 test

.travis.yml

@@ -17,19 +17,18 @@ matrix:
       sudo: false
 
 
-    - env: Ubu=14.04 Cmd="make asan32"
+    - env: Ubu=14.04 Cmd='make -C tests test32 CC=clang-4.0 MOREFLAGS="-g -fsanitize=address"'
       os: linux
       dist: trusty
       sudo: required
       addons:
         apt:
           sources:
-            - ubuntu-toolchain-r-test
+            - llvm-toolchain-trusty-4.0
           packages:
             - libc6-dev-i386
             - gcc-multilib
-            - libclang-3.5-dev
-            - libclang-common-3.5-dev
+            - clang-4.0
 
 
     # Standard Ubuntu 12.04 LTS Server Edition 64 bit