Update GCC on Travis

.travis.yml

@@ -6,6 +6,15 @@ compiler:
 before_install:
   - if [ "$TRAVIS_MCSERVER_BUILD_TYPE" == "COVERAGE" ]; then sudo pip install cpp_coveralls; fi
 
+  # g++4.8
+  - sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test
+  - sudo apt-get update -qq
+
+install:
+  # g++4.8
+  - sudo apt-get install -qq g++-4.8
+  - export CXX="g++-4.8"
+
 # Build MCServer
 script: ./CIbuild.sh