Including tracing setup in all examples (#79)

examples/form.rs

@@ -4,6 +4,8 @@ use std::net::SocketAddr;
 
 #[tokio::main]
 async fn main() {
+    tracing_subscriber::fmt::init();
+
     // build our application with some routes
     let app = route("/", get(show_form).post(accept_form));