Build matrix tweak

.travis.yml

@@ -2,7 +2,7 @@
   # - "sh -e /etc/init.d/xvfb start"
 before_install:
   - "export DISPLAY=:99.0"
-  - "sh -e /etc/init.d/xvfb start"
+  - "test $DEBIAN_FRONTEND && sh -e /etc/init.d/xvfb start"
     #- "sh -e travis-chromium-script.sh"
 script: "DISPLAY=:99.0 bundle exec rake core_spec"
 
@@ -10,8 +10,7 @@ language:
   - ruby
   - objective-c
 
-rvm:
-  - "1.9.3"
+rvm: "1.9.3"
 
 env:
   - JASMINE_BROWSER=firefox
@@ -26,3 +25,6 @@ matrix:
   include:
     - language: objective-c
       env: JASMINE_BROWSER=safari
+  exclude:
+    - language: ruby
+      env: JASMINE_BROWSER=safari