Fixing wrong typing for ClusterWS.subscribe(...) method.

dist/index.d.ts

@@ -10,7 +10,7 @@ export class ClusterWS {
     send(event: string, data: any, type?: string): void;
     disconnect(code?: number, msg?: any): void;
     getState(): number;
-    subscribe(channel: string): void;
+    subscribe(channel: string): Channel;
     getChannelByName(channelName: string): Channel;
 }
 

src/index.ts

@@ -122,7 +122,7 @@ export class ClusterWS {
         return this.websocket.readyState
     }
 
-    public subscribe(channel: string): void {
+    public subscribe(channel: string): Channel {
         return this.channels[channel] ?
             this.channels[channel] :
             this.channels[channel] = new Channel(this, channel)