promisfy bind close

src/socket.js

@@ -1,5 +1,6 @@
 import WebSocket from 'ws'
 import btc from 'better-try-catch'
+import { promisify } from 'util'
 import _ON_DEATH from 'death' //this is intentionally ugly
 import clone from 'clone'
 
@@ -23,6 +24,7 @@ class Socket extends WebSocket.Server {
     //self bindings
     this._listen = this._listen.bind(this)
     this.create = this.create.bind(this)
+    this.close = promisify(this.close).bind(this)
     log = logger({
       file: 'src/socket.js',
       class: 'Socket',