Update node/npm to new version

Updates node to version 5.12 and npm to version whatever. Main point
was to update npm to version greater then 3 because of all the features
it adds at that point.

.nvmrc

@@ -1 +1 @@
-4.2.3
+5.12

README.md

@@ -18,7 +18,7 @@ Learn more about [cloud.gov](https://cloud.gov).
 - `Go` (version 1.6.2)
 
 ### Front end application [![JS Code Coverage Status](https://coveralls.io/repos/18F/cg-deck/badge.svg?branch=master&service=github)](https://coveralls.io/repos/18F/cg-deck/badge.svg?branch=master&service=github)
-- `Node` (version 4.2.3)
+- `Node` (version 5.12.0)
 - `React` (version ^0.14.0)
 
 ## Setup

package.json

@@ -2,8 +2,8 @@
   "name": "cloudgov-dashboard",
   "version": "1.0.0",
   "engines": {
-    "node": "4.2.3",
-    "npm": "2.14.x"
+    "node": "5.12.x",
+    "npm": "3.8.x"
   },
   "description": "A web dashboard for managing Cloud Foundry apps",
   "main": "null",