Merge pull request #1 from ungap/greenkeeper/initial

Update dependencies to enable Greenkeeper 🌴

.travis.yml

@@ -6,5 +6,6 @@ git:
 branches:
   only:
     - master
+    - /^greenkeeper/.*$/
 after_success:
   - "npm run coveralls"

README.md

@@ -1,6 +1,6 @@
 # Essential Set
 
-[![Build Status](https://travis-ci.com/ungap/essential-set.svg?branch=master)](https://travis-ci.com/ungap/essential-set) [![Coverage Status](https://coveralls.io/repos/github/ungap/essential-set/badge.svg?branch=master)](https://coveralls.io/github/ungap/essential-set?branch=master) ![WebReflection status](https://offline.report/status/webreflection.svg)
+[![Build Status](https://travis-ci.com/ungap/essential-set.svg?branch=master)](https://travis-ci.com/ungap/essential-set) [![Coverage Status](https://coveralls.io/repos/github/ungap/essential-set/badge.svg?branch=master)](https://coveralls.io/github/ungap/essential-set?branch=master) [![Greenkeeper badge](https://badges.greenkeeper.io/ungap/essential-set.svg)](https://greenkeeper.io/) ![WebReflection status](https://offline.report/status/webreflection.svg)
 
 An essential [Set](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set) poorlyfill for legacy browsers.
 

package.json

@@ -27,7 +27,7 @@
   "devDependencies": {
     "coveralls": "^3.0.2",
     "istanbul": "^0.4.5",
-    "uglify-js": "^2.8.29"
+    "uglify-js": "^3.4.9"
   },
   "repository": {
     "type": "git",