Updated readme examples to es6

README.md

@@ -12,7 +12,7 @@ Installation
 ------------
 
 ``` bash
-$ npm install spotify-web
+$ npm install spotify-web --save
 ```
 
 
@@ -23,32 +23,30 @@ Here's an example of logging in to the Spotify server and creating a session. Th
 requesting the metadata for a given track URI, and playing the track audio file
 through the speakers:
 
-``` javascript
-var lame = require('lame');
-var Speaker = require('speaker');
-var Spotify = require('spotify-web');
-var uri = process.argv[2] || 'spotify:track:6tdp8sdXrXlPV6AZZN2PE8';
+```js
+const lame = require('lame');
+const Speaker = require('speaker');
+const Spotify = require('spotify-web');
+const uri = process.argv[2] || 'spotify:track:6tdp8sdXrXlPV6AZZN2PE8';
 
 // Spotify credentials...
-var username = process.env.USERNAME;
-var password = process.env.PASSWORD;
+const username = process.env.USERNAME;
+const password = process.env.PASSWORD;
 
-Spotify.login(username, password, function (err, spotify) {
+Spotify.login(username, password, (err, spotify) => {
   if (err) throw err;
 
   // first get a "Track" instance from the track URI
-  spotify.get(uri, function (err, track) {
-    if (err) throw err;
-    console.log('Playing: %s - %s', track.artist[0].name, track.name);
+  spotify.get(uri, (err, track) => {
+    if (err) throw err;
+
+    console.log('Playing: %s - %s', track.artist[0].name, track.name);
 
     // play() returns a readable stream of MP3 audio data
     track.play()
       .pipe(new lame.Decoder())
       .pipe(new Speaker())
-      .on('finish', function () {
-        spotify.disconnect();
-      });
-
+      .on('finish', () => spotify.disconnect());
   });
 });
 ```