try travis matrix

.travis.yml

 language: cpp
 
-compiler:
-  - gcc
+
+matrix:
+  fast_finish: true
+  include:
+    - os: linux
+      env: TOOLSET=clang-3.4
+      addons: &clang34
+        apt:
+          packages:
+            - clang-3.4
+            - libstdc++-5-dev
+            - valgrind
+            - gdb
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-precise-3.4
+
+    - os: linux
+      env: TOOLSET=clang-3.5
+      addons: &clang35
+        apt:
+          packages:
+            - clang-3.5
+            - libstdc++-5-dev
+            - valgrind
+            - gdb
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-precise-3.5
+
+    - os: linux
+      env: TOOLSET=clang-3.6
+      addons: &clang36
+        apt:
+          packages:
+            - clang-3.6
+            - libstdc++-5-dev
+            - valgrind
+            - gdb
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-precise-3.6
+
+    - os: linux
+      env: TOOLSET=clang-3.7
+      addons: &clang37
+        apt:
+          packages:
+            - clang-3.7
+            - libstdc++-5-dev
+            - valgrind
+            - gdb
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-precise
+
+    - os: linux
+      env: TOOLSET=gcc-5
+      addons: &gcc5
+        apt:
+          packages:
+            - g++-5
+            - libstdc++-5-dev
+            - valgrind
+            - gdb
+          sources:
+            - ubuntu-toolchain-r-test
+
+
+#compiler:
+#  - gcc
 
 before_install:
-  - sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y
-  - sudo apt-get update -qq
-  - if [ "$CXX" = "g++" ]; then sudo apt-get install -qq g++-4.9; fi
-  - if [ "$CXX" = "g++" ]; then export CXX="g++-4.9" CC="gcc-4.9"; fi
+#  - sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y
+#  - sudo apt-get update -qq
+#  - if [ "$CXX" = "g++" ]; then sudo apt-get install -qq g++-4.9; fi
+#  - if [ "$CXX" = "g++" ]; then export CXX="g++-4.9" CC="gcc-4.9"; fi
   - sudo pip install cpp-coveralls pyyaml
   - sudo apt-get install valgrind
   - sudo pip install codecov