Restored Travis build on all clang version

.travis.yml

@@ -46,30 +46,30 @@ matrix:
       env: SCRIPT=cmake CMAKE_CXX_COMPILER=g++-5
     - compiler: clang
       env: SCRIPT=cmake CMAKE_CXX_COMPILER=clang++
-    # - compiler: clang
-    #   addons:
-    #     apt:
-    #       sources: ['ubuntu-toolchain-r-test','llvm-toolchain-precise-3.5']
-    #       packages: ['clang-3.5']
-    #   env: SCRIPT=cmake CMAKE_CXX_COMPILER=clang++-3.5
-    # - compiler: clang
-    #   addons:
-    #     apt:
-    #       sources: ['ubuntu-toolchain-r-test','llvm-toolchain-precise-3.6']
-    #       packages: ['clang-3.6']
-    #   env: SCRIPT=cmake CMAKE_CXX_COMPILER=clang++-3.6
-    # - compiler: clang
-    #   addons:
-    #     apt:
-    #       sources: ['ubuntu-toolchain-r-test','llvm-toolchain-precise-3.7']
-    #       packages: ['clang-3.7']
-    #   env: SCRIPT=cmake CMAKE_CXX_COMPILER=clang++-3.7
-    # - compiler: clang
-    #   addons:
-    #     apt:
-    #       sources: ['ubuntu-toolchain-r-test','llvm-toolchain-precise-3.8']
-    #       packages: ['clang-3.8']
-    #   env: SCRIPT=cmake CMAKE_CXX_COMPILER=clang++-3.8
+    - compiler: clang
+      addons:
+        apt:
+          sources: ['ubuntu-toolchain-r-test','llvm-toolchain-precise-3.5']
+          packages: ['clang-3.5']
+      env: SCRIPT=cmake CMAKE_CXX_COMPILER=clang++-3.5
+    - compiler: clang
+      addons:
+        apt:
+          sources: ['ubuntu-toolchain-r-test','llvm-toolchain-precise-3.6']
+          packages: ['clang-3.6']
+      env: SCRIPT=cmake CMAKE_CXX_COMPILER=clang++-3.6
+    - compiler: clang
+      addons:
+        apt:
+          sources: ['ubuntu-toolchain-r-test','llvm-toolchain-precise-3.7']
+          packages: ['clang-3.7']
+      env: SCRIPT=cmake CMAKE_CXX_COMPILER=clang++-3.7
+    - compiler: clang
+      addons:
+        apt:
+          sources: ['ubuntu-toolchain-r-test','llvm-toolchain-precise-3.8']
+          packages: ['clang-3.8']
+      env: SCRIPT=cmake CMAKE_CXX_COMPILER=clang++-3.8
     - compiler: gcc
       env: SCRIPT=coverage
     - os: osx