Add promise and fetch polyfills to build

Previously we were polyfilling using webpack, which of course only affected the demo and not the actual build
Fixes cookpete/react-player#39

package.json

@@ -81,12 +81,13 @@
     "style-loader": "^0.13.0",
     "webpack": "^1.12.9",
     "webpack-dev-middleware": "^1.4.0",
-    "webpack-hot-middleware": "^2.6.0",
-    "whatwg-fetch": "^0.11.0"
+    "webpack-hot-middleware": "^2.6.0"
   },
   "dependencies": {
+    "es6-promise": "^3.1.2",
     "load-script": "^1.0.0",
-    "query-string": "^3.0.0"
+    "query-string": "^3.0.0",
+    "whatwg-fetch": "^0.11.0"
   },
   "standard": {
     "parser": "babel-eslint",

src/ReactPlayer.js

@@ -1,3 +1,5 @@
+import 'es6-promise'
+import 'whatwg-fetch'
 import React, { Component } from 'react'
 
 import { propTypes, defaultProps } from './props'

webpack.config.dev.js

@@ -14,10 +14,7 @@ module.exports = {
   },
   plugins: [
     new webpack.HotModuleReplacementPlugin(),
-    new webpack.NoErrorsPlugin(),
-    new webpack.ProvidePlugin({
-      'fetch': 'imports?this=>global!exports?global.fetch!whatwg-fetch'
-    })
+    new webpack.NoErrorsPlugin()
   ],
   module: {
     loaders: [{