Support stricter type

Author: ryo-ma

deps.ts

@@ -6,5 +6,8 @@ export {
   isWebSocketPingEvent,
   isWebSocketPongEvent,
   connectWebSocket,
-  WebSocket,    
 } from "https://deno.land/std@0.65.0/ws/mod.ts";
+
+export type {
+  WebSocket,
+} from "https://deno.land/std@0.65.0/ws/mod.ts";

mod.ts

@@ -1,2 +1,2 @@
-export { WebSocketServer, WebSocket, WebSocketState } from "./lib/websocket.ts";
-export { WebSocketError } from "./lib/errors.ts";
+export type { WebSocketServer, WebSocket, WebSocketState } from "./lib/websocket.ts";
+export type { WebSocketError } from "./lib/errors.ts";