Update package.json (#3480)

* Update package.json

* Update .travis.yml

.travis.yml

@@ -1,7 +1,7 @@
 language: node_js
 dist: trusty
 node_js:
-- '4.5'
+- '4.6'
 - '6.1'
 services:
   - postgresql

package.json

@@ -78,7 +78,7 @@
     "prepublish": "npm run build"
   },
   "engines": {
-    "node": ">=4.5"
+    "node": ">=4.6"
   },
   "bin": {
     "parse-server": "./bin/parse-server"