remove g++4.8 from travis on macos as the installation is broken and conflicting with pre-installed c++ versions..

Author: Cylix

.travis.yml

@@ -24,13 +24,12 @@ addons:
 
 before_install:
   - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew update; fi
-  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew install gcc48 --enable-cxx; fi
   - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew install llvm --with-clang; fi
 
 install:
   - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew install ccache; fi
   - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then export PATH="/usr/local/opt/ccache/libexec:$PATH"; fi
-  - if [ "$CXX" = "g++" ]; then export CXX="g++-4.8" CC="gcc-4.8"; fi
+  - if [[ "$TRAVIS_OS_NAME" != "osx" && "$CXX" = "g++" ]]; then export CXX="g++-4.8" CC="gcc-4.8"; fi
   - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew install redis; fi
   - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then (redis-server&); fi