chore(ci): specify node version

Ryan-Git · Ryan-Git · commit e28e597c559d · 2018-12-28T18:22:54.000+08:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,5 +1,8 @@
 language: node_js
 
+node_js:
+  - "node"
+
 jobs:
   include:
     - name: "build"
