Remove buffer dependency

src/messages/keepalive.ts

@@ -8,9 +8,9 @@ const MESSAGE_TYPE = numberToUint16BE(MessageTypes.Keepalive)
  * Create an outgoing keepalive (0x0005) packet.
  * @returns An outgoing keepalive (0x0005) packet.
  */
-export function packKeepaliveMessage (): Buffer {
+export function packKeepaliveMessage (): Uint8Array {
   return packOutgoingPacket({
     messageType: MESSAGE_TYPE,
-    data: Buffer.alloc(0)
+    data: new Uint8Array(0)
   })
 }