Receiver#createStream should take options

src/client/voice/receiver/Receiver.js

@@ -10,12 +10,12 @@ class VoiceReceiver extends EventEmitter {
     this.connection.sockets.udp.socket.on('message', buffer => this.packets.push(buffer));
   }
 
-  createStream(user, pcm=false) {
+  createStream(user, { mode = 'opus' } = {}) {
     user = this.connection.client.users.resolve(user);
     if (!user) throw new Error('VOICE_USER_MISSING');
     console.log('making stream for', user.tag);
     const stream = this.packets.makeStream(user.id);
-    if (pcm) {
+    if (mode === 'pcm') {
       const decoder = new prism.opus.Decoder({ channels: 2, rate: 48000, frameSize: 1920 });
       stream.pipe(decoder);
       return decoder;

src/client/voice/receiver/VoiceReadable.js

@@ -3,15 +3,9 @@ const { Readable } = require('stream');
 class VoiceReadable extends Readable {
   constructor() {
     super();
-    this._packets = [];
-    this.open = true;
   }
 
   _read() {} // eslint-disable-line no-empty-function
-
-  _push(d) {
-    if (this.open) this.push(d);
-  }
 }
 
 module.exports = VoiceReadable;