Only use Node 6 as the testing Node.js version. (vercel#2609)

arunoda · web-flow · commit 89d4e0af4aff · 2017-07-20T22:19:32.000+05:30
It's safe to use this as we don't use any platform specific Node.js features.
diff --git a/.travis.yml b/.travis.yml
@@ -8,7 +8,6 @@ addons:
       - google-chrome-stable
 language: node_js
 node_js:
-  - "4"
   - "6"
 cache:
   directories:
diff --git a/appveyor.yml b/appveyor.yml
@@ -1,6 +1,5 @@
 environment:
   matrix:
-    - nodejs_version: "4"
     - nodejs_version: "6"
 
 # Install scripts. (runs after repo cloning)
