message: Improved self update in windows
diff: //! When wasmer self-update is executed, this is what gets executed
  -use anyhow::Result;
  +use anyhow::{bail, Result};
  #[cfg(not(target_os = "windows"))]
  use std::process::{Command, Stdio};
  use structopt::StructOpt;
  @@ -31,6 +31,6 @@ impl SelfUpdate {
  #[cfg(target_os = "windows")]
  /// The execute subcommand (for Windows)
  pub fn execute(&self) -> Result<()> {
  - println!("Self update is not supported on Windows. Use install instructions on the Wasmer homepage: https://wasmer.io");
  + bail!("Self update is not supported on Windows. Use install instructions on the Wasmer homepage: https://wasmer.io");
  }
  }
  