websocket cleanup (#1346)

* websocket cleanup

* resume event

* Update Resumed.js

* Update WebSocketManager.js

src/client/websocket/packets/handlers/Resumed.js

@@ -0,0 +1,26 @@
+const AbstractHandler = require('./AbstractHandler');
+
+class ResumedHandler extends AbstractHandler {
+  handle(packet) {
+    const client = this.packetManager.client;
+    const ws = client.ws;
+
+    ws._trace = packet.d._trace;
+
+    const replayed = ws.sequence - ws.resumeStart;
+    ws.resumeStart = -1;
+
+    client.emit('debug', `RESUMED ${ws._trace.join(' -> ')} | replayed ${replayed} events. `);
+    client.emit('resume', replayed);
+
+    ws.heartbeat();
+  }
+}
+
+/**
+ * Emitted whenever a websocket resumes
+ * @event Client#resume
+ * @param {Number} replayed Number of events that were replayed
+ */
+
+module.exports = ResumedHandler;