Added support for Clang 5.0. Fixes #365 (#388)

.travis.yml

@@ -20,6 +20,8 @@ matrix:
       os: linux
     - env: SCRIPT=test CLANG=3.8
       os: linux
+    - env: SCRIPT=test CLANG=5.0
+      os: linux
     - env: SCRIPT=lint CLANG=3.9
       os: linux
 
@@ -28,7 +30,7 @@ before_install:
       if [ "$TRAVIS_OS_NAME" = "linux" ]; then
         wget -O - http://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
         sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y
-        sudo apt-add-repository "deb http://apt.llvm.org/precise/ llvm-toolchain-precise-$CLANG main"
+        sudo apt-add-repository "deb http://apt.llvm.org/trusty/ llvm-toolchain-trusty-$CLANG main"
         sudo apt-get update
         sudo apt-cache search clang
         sudo apt-get install -f -y --force-yes clang-$CLANG lldb-$CLANG