Fix: AudioClass does not have member 'close', use 'end' instead. (#29)

examples/SimpleAudioPlayerZero/SimpleAudioPlayerZero.ino

@@ -56,7 +56,7 @@ void loop()
 
   // until the file is not finished  
   AudioZero.play(myFile);
-  AudioZero.close();
+  AudioZero.end();
   Serial.println("End of file. Thank you for listening!");
   while (true) ;
 }