Update Node in Travis

Author: wooorm

.travis.yml

@@ -1,7 +1,7 @@
 language: node_js
 node_js:
 - '4.0'
-- '7.0'
+- '8.0'
 sudo: false
 after_success:
 - bash <(curl -s https://codecov.io/bash)
@@ -22,4 +22,4 @@ deploy:
     skip_cleanup: true
     on:
       tags: true
-      node: '7.0'
+      node: '8.0'