Upgrade GCC from 4.8 to 4.9

Author: LinusU

.travis.yml

@@ -14,9 +14,9 @@ addons:
       - libjpeg8-dev
       - libpango1.0-dev
       - libgif-dev
-      - g++-4.8
+      - g++-4.9
 env:
-  - CXX=g++-4.8
+  - CXX=g++-4.9
 before_install:
   - if [[ $TRAVIS_NODE_VERSION == 0.8 ]]; then npm install -g npm@1.4.28; fi
   - npm explore npm -g -- npm install node-gyp@latest