
The `(dockerPusher).Push` method uses a `StatusTracker` to check if an upload already happened, before repeating the upload. However, there is no provision for failure handling. If a PUT request returns an error, the `StatusTracker` will still see the upload as if it happened successfully. Add a status boolean so that only successful uploads short-circuit `Push`. Signed-off-by: Aaron Lehmann <alehmann@netflix.com>