message: Assert fix::doesnt_rebuild_dependencies stderr fully
  Gives more confidence.
diff: @@ -1065,14 +1065,19 @@ fn doesnt_rebuild_dependencies() {
  p.cargo("fix --allow-no-vcs -p foo")
  .env("__CARGO_FIX_YOLO", "1")
  .with_stdout("")
  - .with_stderr_contains("[CHECKING] bar v0.1.0 ([..])")
  - .with_stderr_contains("[CHECKING] foo v0.1.0 ([..])")
  + .with_stderr("\
  +[CHECKING] bar v0.1.0 ([..])
  +[CHECKING] foo v0.1.0 ([..])
  +[FINISHED] dev [unoptimized + debuginfo] target(s) in [..]
  +")
  .run();
  p.cargo("fix --allow-no-vcs -p foo")
  .env("__CARGO_FIX_YOLO", "1")
  .with_stdout("")
  - .with_stderr_does_not_contain("[CHECKING] bar v0.1.0 ([..])")
  - .with_stderr_contains("[CHECKING] foo v0.1.0 ([..])")
  + .with_stderr("\
  +[CHECKING] foo v0.1.0 ([..])
  +[FINISHED] dev [unoptimized + debuginfo] target(s) in [..]
  +")
  .run();
  }
  