build(node): upgrade to node 5.4.1

.nvmrc

@@ -1 +1 @@
-4.2.1
+5.4.1

.travis.yml

@@ -1,7 +1,7 @@
 language: node_js
 sudo: false
 node_js:
-- '4.2.1'
+- '5.4.1'
 
 branches:
   except:
@@ -60,7 +60,7 @@ addons:
   firefox: "38.0"
 
 before_install:
-- npm install -g npm@3.5.2
+- npm install -g npm@3.5.3
 - node tools/analytics/build-analytics start ci job
 - node tools/analytics/build-analytics start ci before_install
 - echo ${TSDRC} > .tsdrc

circle.yml

@@ -1,6 +1,6 @@
 machine:
   node:
-    version: 4.2.1
+    version: 5.4.1
 test:
   override:
     - npm run build

gulpfile.js

@@ -3,7 +3,7 @@
 // THIS CHECK SHOULD BE THE FIRST THING IN THIS FILE
 // This is to ensure that we catch env issues before we error while requiring other dependencies.
 require('./tools/check-environment')(
-    {requiredNpmVersion: '>=3.5.2 <4.0.0', requiredNodeVersion: '>=4.2.1 <5.0.0'});
+    {requiredNpmVersion: '>=3.5.3 <4.0.0', requiredNodeVersion: '>=5.4.1 <6.0.0'});
 
 
 var fse = require('fs-extra');

package.json

@@ -19,7 +19,7 @@
   ],
   "license": "MIT",
   "engines": {
-    "node": ">= 4.2.1 < 5"
+    "node": ">= 5.4.1 < 6"
   },
   "repository": {
     "type": "git",