Remove pub visibility on server() as the argument has a private typ…

…e. This gets rid of a warning. (#112)

exercises/07_threads/08_client/src/lib.rs

@@ -38,7 +38,7 @@ enum Command {
     },
 }
 
-pub fn server(receiver: Receiver<Command>) {
+fn server(receiver: Receiver<Command>) {
     let mut store = TicketStore::new();
     loop {
         match receiver.recv() {