Cherry pick commits from indev

src/client/Client.js

@@ -236,8 +236,8 @@ class Client extends EventEmitter {
   destroy() {
     for (const t of this._timeouts) clearTimeout(t);
     for (const i of this._intervals) clearInterval(i);
-    this._timeouts = [];
-    this._intervals = [];
+    this._timeouts.clear();
+    this._intervals.clear();
     this.token = null;
     this.email = null;
     this.password = null;

src/client/ClientManager.js

@@ -58,10 +58,10 @@ class ClientManager {
   }
 
   destroy() {
-    return new Promise((resolve) => {
+    return new Promise((resolve, reject) => {
       this.client.ws.destroy();
       if (!this.client.user.bot) {
-        this.client.rest.methods.logout().then(resolve);
+        this.client.rest.methods.logout().then(resolve, reject);
       } else {
         resolve();
       }

src/client/voice/ClientVoiceManager.js

@@ -80,7 +80,7 @@ class ClientVoiceManager {
     return new Promise((resolve, reject) => {
       if (this.pending.get(channel.guild.id)) throw new Error('Already connecting to this guild\'s voice server.');
 
-      if (!channel.permissionsFor(this.client.user).hasPermission('CONNECT')) {
+      if (!channel.joinable) {
         throw new Error('You do not have permission to join this voice channel');
       }
 

src/client/voice/VoiceWebSocket.js

@@ -142,7 +142,6 @@ class VoiceWebSocket extends EventEmitter {
    * Called whenever the connection to the WebSocket Server is lost
    */
   onClose() {
-    // TODO see if the connection is open before reconnecting
     if (!this.dead) this.client.setTimeout(this.connect.bind(this), this.attempts * 1000);
   }
 

src/client/voice/util/SecretKey.js

@@ -1,5 +1,6 @@
 /**
  * Represents a Secret Key used in encryption over voice
+ * @private
  */
 class SecretKey {
   constructor(key) {