Fix travis build for MacVim

.travis.yml

@@ -28,12 +28,6 @@ before_install:
   - brew install python3
   - brew install lua
 
-# Start virtual framebuffer to be able to test the GUI.
-before_script:
-  - "export DISPLAY=:99.0"
-  - "sh -e /etc/init.d/xvfb start"
-  - sleep 3 # give xvfb some time to start
-
 script:
   - NPROC=$(getconf _NPROCESSORS_ONLN)
   - ./configure $CONFOPT --enable-fail-if-missing