.travis.yml in volay-1.0.1 vs .travis.yml in volay-1.1.0

@@ -1,12 +1,14 @@
 language: ruby
 rvm:
-  - 1.9.3
-  - 2.0.0
-  - 2.1.0
+  - 2.2.5
+  - 2.3.1
 
+env:
+  global:
+    - DISPLAY=":99.0"
+
 before_install:
-  - export DISPLAY=:99.0
   - sh -e /etc/init.d/xvfb start
 
 script: bundle exec rake
 
 addons: