Force node 4.3

Node 4.1 has a security vulnerability. Lets update our Node.

https://nodejs.org/en/blog/vulnerability/february-2016-security-releases/

Author: drew-gross

package.json

@@ -45,7 +45,7 @@
     "prepublish": "npm run build"
   },
   "engines": {
-    "node": ">=4.1"
+    "node": ">=4.3"
   },
   "bin": {
     "parse-server": "./bin/parse-server"