[Tests] on io.js v3.3, up to node v4.1

Author: ljharb

.travis.yml

@@ -1,5 +1,8 @@
 language: node_js
 node_js:
+  - "4.1"
+  - "4.0"
+  - "iojs-v3.3"
   - "iojs-v3.2"
   - "iojs-v3.1"
   - "iojs-v3.0"
@@ -31,6 +34,8 @@ sudo: false
 matrix:
   fast_finish: true
   allow_failures:
+    - node_js: "4.0"
+    - node_js: "iojs-v3.2"
     - node_js: "iojs-v3.1"
     - node_js: "iojs-v3.0"
     - node_js: "iojs-v2.4"