homework: extract print_status into a separate trait

smart-house/src/lib.rs

@@ -4,11 +4,13 @@ mod house;
 mod power_socket;
 #[macro_use]
 mod room;
+mod print_status;
 mod thermometer;
 
 pub use device::Device;
 pub use error::Error;
 pub use house::House;
 pub use power_socket::PowerSocket;
+pub use print_status::PrintStatus;
 pub use room::Room;
 pub use thermometer::Thermometer;