Fix travis config by moving CTEST_OUTPUT_ON_FAILURE=1 into make test command

.travis.yml

@@ -13,9 +13,6 @@ matrix:
     - os: osx
       env: BUILD_TYPE=Release STD=c++11
 
-env:
-    - CTEST_OUTPUT_ON_FAILURE=1
-
 language:
     - cpp
 
@@ -33,4 +30,4 @@ before_script:
 script:
     - cmake .. -DCMAKE_BUILD_TYPE=${BUILD_TYPE} -DCMAKE_CXX_FLAGS="-std=${STD}"
     - make
-    - make test
+    - make CTEST_OUTPUT_ON_FAILURE=1 test