Update dependencies to enable Greenkeeper 🌴 (#3)

* chore(package): update dependencies

https://greenkeeper.io/

* docs(readme): add Greenkeeper badge 

https://greenkeeper.io/

Author: greenkeeper[bot]

README.md

@@ -1,5 +1,7 @@
 # Deep Object Diff
 
+[![Greenkeeper badge](https://badges.greenkeeper.io/mattphillips/deep-object-diff.svg)](https://greenkeeper.io/)
+
 [![Build Status](https://travis-ci.org/mattphillips/deep-object-diff.svg?branch=master)](https://travis-ci.org/mattphillips/deep-object-diff)
 [![Coverage Status](https://coveralls.io/repos/github/mattphillips/deep-object-diff/badge.svg?branch=master)](https://coveralls.io/github/mattphillips/deep-object-diff?branch=master)
 

package.json

@@ -20,7 +20,7 @@
   "devDependencies": {
     "babel-cli": "^6.18.0",
     "babel-core": "^6.18.2",
-    "babel-istanbul": "^0.11.0",
+    "babel-istanbul": "^0.12.1",
     "babel-plugin-add-module-exports": "^0.2.1",
     "babel-plugin-transform-es2015-modules-umd": "^6.22.0",
     "babel-preset-es2015": "^6.18.0",