fix travis config

Author: le0pard

.travis.yml

@@ -1,14 +1,14 @@
 before_script:
   - "sh -e /etc/init.d/xvfb start"
+before_install:
+  - gem install bundler
 script: "sh -c 'export DISPLAY=:99.0 && test/test.sh'"
 language: ruby
 services:
   - mongodb
 rvm:
   - 1.9.2
   - 1.9.3
-#  - ruby-head
-#  - jruby-head
 notifications:
   email: false
 branches:
@@ -17,3 +17,7 @@ branches:
     - development
     - gem
 #bundler_args: --path vendor/bundle
+matrix:
+  allow_failures:
+    - rvm: ruby-head
+    - rvm: jruby-head