message: refactor: Import self and use full module path for failure
  Use full module path for failure to be consistent since
  it's used like that in other modules.
diff: @@ -23,7 +23,7 @@ use std::path::Path;
  use std::process;
  use atty;
  -use failure::{Error, ResultExt};
  +use failure::{self, ResultExt};
  use which;
  pub fn install() -> ! {
  @@ -47,7 +47,7 @@ pub fn install() -> ! {
  process::exit(0);
  }
  -fn do_install() -> Result<(), Error> {
  +fn do_install() -> Result<(), failure::Error> {
  // Find `rustup.exe` in PATH, we'll be using its installation directory as
  // our installation directory.
  let rustup = match which::which("rustup") {
  @@ -85,7 +85,7 @@ fn do_install() -> Result<(), Error> {
  Ok(())
  }
  -fn confirm_can_overwrite(dst: &Path) -> Result<(), Error> {
  +fn confirm_can_overwrite(dst: &Path) -> Result<(), failure::Error> {
  // If the `-f` argument was passed, we can always overwrite everything.
  if env::args().any(|arg| arg == "-f") {
  return Ok(());
  