fix(travis-ci): bump node version

jbailey4 · jbailey4 · commit 7e01aff722d7 · 2018-07-31T22:13:25.000-04:00
diff --git a/.travis.yml b/.travis.yml
@@ -3,7 +3,7 @@ language: node_js
 node_js:
   # we recommend testing addons with the same minimum supported node version as Ember CLI
   # so that your addon works for all apps
-  - "4"
+  - "6"
 
 sudo: required
 dist: trusty
