[FEATURE] update to latest node version

core/node.sh

-nodeversion="6.6.0"
+nodeversion="6.7.0"

package.json

@@ -13,7 +13,7 @@
   "license": "SEE LICENSE IN LICENSE.md",
   "devDependencies": {},
   "engines": {
-    "node": "~6.6.0"
+    "node": "~6.7.0"
   },
   "dependencies": {
     "babel-preset-es2015": "^6.14.0",