Migrate to xenial in travis

cherifGsoul · cherifGsoul · commit e8a452041719 · 2019-06-14T00:18:41.000+01:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,7 +1,7 @@
 language: node_js
 node_js: node
 addons:
-  firefox: "51.0"
-before_install:
-  - "export DISPLAY=:99.0"
-  - "sh -e /etc/init.d/xvfb start"
+  firefox: '51.0'
+dist: xenial
+services:
+  - xvfb
