Another attempt to get travis to upgrade gcc

.travis.yml

@@ -6,11 +6,12 @@ before_install:
     - sh -e /etc/init.d/xvfb start
     
     # Upgrade gcc
-    - sudo apt-get update -qq
-    - sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-4.8 90
+    - sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test
+    - sudo apt-get -qq update 
+    - sudo apt-get -qq install g++-4.8
     
     # Install dependencies
-    - sudo apt-get install -qq libwxgtk3.0-dev libwxgtk3.0-0 libssh2-1-dev
+    - sudo apt-get -qq install libwxgtk3.0-dev libwxgtk3.0-0 libssh2-1-dev
 
 # Build with both gcc and clang
 compiler: