And another attempt.

.travis.yml

@@ -26,8 +26,8 @@ before_install:
       sudo apt-get install cmake;
       sudo apt-get install libboost1.55-all-dev;
       wget https://github.com/Itseez/opencv/archive/3.1.0.zip;
-      unzip 3.1.0.zip;
-      opencv-3.1.0;
+      unzip 3.1.0.zip -q;
+      cd opencv-3.1.0;
       mkdir build;
       cd build;
     fi
@@ -51,7 +51,8 @@ before_install:
   - if [ ${TRAVIS_OS_NAME} = osx ]; then  
       brew update;
       brew install tbb;
-      brew install homebrew/science/opencv || brew link --overwrite homebrew/python/numpy
+      brew install homebrew/science/opencv
+      homebrew/python/numpy
     fi
 
 before_script: