fix(logging): adjust several logging messages

Closes #148

examples/hello.rs

@@ -13,4 +13,5 @@ fn hello(_: Request, res: Response) {
 
 fn main() {
     hyper::Server::http(Ipv4Addr(127, 0, 0, 1), 3000).listen(hello).unwrap();
+    println!("Listening on http://127.0.0.1:3000");
 }

examples/server.rs

@@ -52,4 +52,5 @@ fn echo(mut req: Request, mut res: Response) {
 fn main() {
     let server = Server::http(Ipv4Addr(127, 0, 0, 1), 1337);
     server.listen(echo).unwrap();
+    println!("Listening on http://127.0.0.1:1337");
 }