[skip ci] update travis config to firefox latest

dfreedm · dfreedm · commit 698e8e429dc1 · 2015-12-15T13:53:16.000-08:00
diff --git a/.travis.yml b/.travis.yml
@@ -2,7 +2,7 @@ language: node_js
 sudo: false
 node_js: 4
 addons:
-  firefox: '42.0'
+  firefox: latest
   apt:
     sources:
     - google-chrome
