Function detect_source_cargo_with_home_only

atomic-cli/src/commands/update.rs:776–780

()

    #[test]
    fn detect_source_cargo_with_home_only() {
        let env = MockEnv::new().set("HOME", "/u/me");
        let p = Path::new("/u/me/.cargo/bin/atomic");
        assert_eq!(detect_source(p, &env), InstallSource::Cargo);
    }

    #[test]
    fn detect_source_random_path_is_manual() {