Example with `run_tcp`

[vit1251]

Could you please add another one example where Rust application run on port 9000 with run_tcp instead run. Source code with example shown below.

use std::net::{TcpListener};
use std::io::Write;

use fastcgi::{Request};

fn handle_request(mut req: Request) {
    write!(&mut req.stdout(), "Content-Type: text/plain\n\nHello, world!").unwrap_or(());
}

fn main() {
    let listener = TcpListener::bind("127.0.0.1:9000").unwrap();
    fastcgi::run_tcp(handle_request, &listener);
}