feat: adding header support for client

v1/examples/server/main.go

@@ -17,7 +17,7 @@ func main() {
 	s, err := server.NewSafeWebsocketServerBuilder().
 		BaseHost("localhost").
 		BasePort(8080).
-		ApiKey("").
+		ApiKey("abcd").
 		HandleFuncWebsocket("/ws/test/", "data_1", func(c chan []byte) {
 			ticker := time.NewTicker(10 * time.Millisecond)
 			for range ticker.C {