message: Improve human_addr_implements_display test
diff: @@ -119,9 +119,11 @@ mod test {
  }
  #[test]
  - fn human_addr_format() {
  - let human_addr = HumanAddr::from("Hello, world!");
  - assert_eq!("Hello, world!", format!("{}", human_addr));
  + fn human_addr_implements_display() {
  + let human_addr = HumanAddr::from("cos934gh9034hg04g0h134");
  + let embedded = format!("Address: {}", human_addr);
  + assert_eq!(embedded, "Address: cos934gh9034hg04g0h134");
  + assert_eq!(human_addr.to_string(), "cos934gh9034hg04g0h134");
  }
  #[test]
  