fix select_test's suggestion on how to run it

--bin might've worked on cargo cca. 2018 ? unsure
but --example works today

examples/select_test.rs

@@ -4,7 +4,7 @@
 // cargo test --example select_test -- --nocapture
 
 fn main() {
- print!("To run this example call:\n$ cargo test --bin select_test -- --nocapture\n");
+ println!("To run this example call:\n$ cargo test --example select_test -- --nocapture");
 }
 
 #[cfg(test)]