Fix upgrade command docopt USAGE string.
@@ -21,7 +21,7 @@ static USAGE: &'static str = r"
Upgrade all dependencies in a manifest file to the latest version.
Usage:
- cargo upgrade [--all] [--dependency <dep>...] [--manifest-path <path>]
+ cargo upgrade [--all] [--dependency <dep>...] [--manifest-path <path>] [options]
cargo upgrade (-h | --help)
cargo upgrade (-V | --version)
