build: Add Node 6 and Node 7 support

Fixes #133

Author: Krinkle

.travis.yml

@@ -1,6 +1,8 @@
 sudo: false
 language: node_js
 node_js:
+  - '7'
+  - '6'
   - '4.1.1'
   - '0.12'
   - '0.11'

package.json

@@ -30,7 +30,7 @@
     "qunit": "./bin/cli.js"
   },
   "engines": {
-    "node": ">=0.6.0 < 5.0"
+    "node": ">=0.6.0 < 8.0"
   },
   "scripts": {
     "test": "node --harmony ./test/testrunner.js"