Update travis script

Author: darkriszty

.travis.yml

@@ -8,10 +8,10 @@ os:
 - linux
 
 before_install:
-  - if [ $TRAVIS_OS_NAME == "linux" ]; then
-      export CXX="g++-4.9" CC="gcc-4.9" DISPLAY=:99.0;
-      sh -e /etc/init.d/xvfb start;
-      sleep 3;
+  - |
+    if [ $TRAVIS_OS_NAME == "linux" ]; then
+      export DISPLAY=':99.0'
+      /usr/bin/Xvfb :99 -screen 0 1024x768x24 > /dev/null 2>&1 &
     fi
 
 install: