[master] 04288d7 Build with clang 5.0

[Federico G. Schwindt]

commit 04288d709e6fd55108286c9dcc77315f788edb01
Author: Federico G. Schwindt <fgsch at lodoss.net>
Date:   Sun Oct 22 00:28:34 2017 -0700

    Build with clang 5.0

diff --git a/.travis.yml b/.travis.yml
index a3b1cb5..a32b5d5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -13,13 +13,13 @@ matrix:
   - os: linux
     dist: trusty
     compiler: clang
-    env: CLANG=4.0
+    env: CLANG=5.0
   - os: osx
     osx_image: xcode9
     compiler: clang
   allow_failures:
   - os: osx
-  - env: CLANG=4.0
+  - env: CLANG=5.0
 addons:
   apt:
     packages: