Fixed chrome install in travis (#495)

.travis.yml

@@ -1,11 +1,14 @@
 language: node_js
 node_js:
 - '0.12'
+dist: trusty
+addons:
+  apt:
+    sources:
+    - google-chrome
+    packages:
+    - google-chrome-stable
 before_install:
-- wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo apt-key add -
-- sudo sh -c 'echo "deb http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list'
-- sudo apt-get update || true
-- sudo apt-get install google-chrome-stable
 - export DISPLAY=:99.0
 - sh -e /etc/init.d/xvfb start
 - ./kickstart.sh