Use fetch-jsonp for SoundCloud resolve endpoint

Also removes the need for fetch polyfill
Fixes cookpete/react-player#24
Should also fix cookpete/react-player#47

package.json

@@ -85,15 +85,12 @@
   },
   "dependencies": {
     "es6-promise": "^3.1.2",
+    "fetch-jsonp": "^1.0.0",
     "load-script": "^1.0.0",
-    "query-string": "^4.1.0",
-    "whatwg-fetch": "^1.0.0"
+    "query-string": "^4.1.0"
   },
   "standard": {
     "parser": "babel-eslint",
-    "global": [
-      "fetch"
-    ],
     "ignore": [
       "/dist/*"
     ]

src/ReactPlayer.js

@@ -1,5 +1,4 @@
 import 'es6-promise'
-import 'whatwg-fetch'
 import React, { Component } from 'react'
 
 import { propTypes, defaultProps } from './props'

src/players/SoundCloud.js

@@ -1,5 +1,6 @@
 import React from 'react'
 import loadScript from 'load-script'
+import fetchJSONP from 'fetch-jsonp'
 
 import Base from './Base'
 
@@ -43,15 +44,13 @@ export default class SoundCloud extends Base {
     if (songData[url]) {
       return Promise.resolve(songData[url])
     }
-    return fetch(RESOLVE_URL + '?url=' + url + '&client_id=' + this.props.soundcloudConfig.clientId)
+    return fetchJSONP(RESOLVE_URL + '?url=' + url + '&client_id=' + this.props.soundcloudConfig.clientId)
       .then(response => {
-        if (response.status >= 200 && response.status < 300) {
+        if (response.ok) {
           songData[url] = response.json()
           return songData[url]
         } else {
-          const error = new Error(response.statusText)
-          error.response = response
-          throw error
+          this.props.onError(new Error('SoundCloud track could not be resolved'))
         }
       })
   }