message: Add printing URL info in terminal::open_browser
diff: +use crate::terminal::message::{Message, StdOut};
  use std::process::{Command, Stdio};
  pub fn open_browser(url: &str) -> Result<(), failure::Error> {
  @@ -27,5 +28,7 @@ pub fn open_browser(url: &str) -> Result<(), failure::Error> {
  .spawn()?;
  };
  + let msg = format!("Opened a link in your default browser: {}", url);
  + StdOut::info(&msg);
  Ok(())
  }
  