Tentative fix of TravisCI

.travis.yml

@@ -1,44 +1,45 @@
-language: cpp
-
 matrix:
   include:
     - os: linux
-        addons:
-          apt:
-            sources:
-              - ubuntu-toolchain-r-test
-            packages:
-              - g++-4.9
-        env:
-          - MATRIX_EVAL="CC=gcc-4.9 && CXX=g++-4.9"
+      addons:
+        apt:
+          sources:
+            - ubuntu-toolchain-r-test
+          packages:
+            - g++-4.9
+      env:
+        - MATRIX_EVAL="CC=gcc-4.9 && CXX=g++-4.9"
+
     - os: linux
-        addons:
-          apt:
-            sources:
-              - ubuntu-toolchain-r-test
-            packages:
-              - g++-7
-        env:
-          - MATRIX_EVAL="CC=gcc-7 && CXX=g++-7"
+      addons:
+        apt:
+          sources:
+            - ubuntu-toolchain-r-test
+          packages:
+            - g++-7
+      env:
+        - MATRIX_EVAL="CC=gcc-7 && CXX=g++-7"
+
     - os: osx
-        addons:
-          apt:
-            sources:
-              - ubuntu-toolchain-r-test
-              - llvm-toolchain-precise-3.6
-            packages:
-              - clang-3.6
-        env:
-          - MATRIX_EVAL="CC=clang-3.6 && CXX=clang++-3.6"
+      addons:
+        apt:
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-precise-3.6
+          packages:
+            - clang-3.6
+      env:
+        - MATRIX_EVAL="CC=clang-3.6 && CXX=clang++-3.6"
+
     - os: osx
-        addons:
-          apt:
-            sources:
-              - llvm-toolchain-trusty-5.0
-            packages:
-              - clang-5.0
-        env:
-          - MATRIX_EVAL="CC=clang-5.0 && CXX=clang++-5.0"
+      addons:
+        apt:
+          sources:
+            - llvm-toolchain-trusty-5.0
+          packages:
+            - clang-5.0
+      env:
+        - MATRIX_EVAL="CC=clang-5.0 && CXX=clang++-5.0"
 
 before_install:
     - eval "${MATRIX_EVAL}"