Up the version of node to the required version

package.json

@@ -34,7 +34,7 @@
     "main": "./dist/less-1.6.3.js"
   },
   "engines": {
-    "node": ">=0.4.2"
+    "node": ">=0.8.0"
   },
   "scripts": {
     "test": "grunt test"
@@ -85,4 +85,4 @@
     "variables in css",
     "css less"
   ]
-}
+}