Travis CI compiler versions

.travis.yml

@@ -1,21 +1,24 @@
-language: cpp
+language: gneric
 sudo: required
 os: linux
 dist: trusty
 matrix:
   include:
-    # works on Precise and Trusty
     - os: linux
+      env: COMPILER_NAME=gcc CXX=g++-7 CC=gcc-7
       addons:
         apt:
-          sources:
-            - ubuntu-toolchain-r-test
           packages:
             - g++-7
-      env:
-         - MATRIX_EVAL="CC=gcc-7 && CXX=g++-7"
-before_install:
-    - eval "${MATRIX_EVAL}"         
+          sources:
+            - ubuntu-toolchain-r-test
+    - os: linux
+      env: COMPILER_NAME=clang CXX=clang++-5.0 CC=clang-5.0
+      addons:
+        apt:
+          packages:
+            - clang-5.0
+          sources: *sources   
 compiler:
   - clang
   - gcc