fix apt repository used on Travis CI

rhysd · rhysd · commit 317eb48e7734 · 2016-04-16T23:10:26.000+09:00
diff --git a/.travis.yml b/.travis.yml
@@ -15,7 +15,7 @@ script:
 addons:
     apt:
         sources:
-            - llvm-toolchain-precise
+            - llvm-toolchain-precise-3.8
             - llvm-toolchain-precise-3.7
             - ubuntu-toolchain-r-test
         packages:
