Bytearray, print value non ascii

RustPytho:

```
>>>>> bytearray([11,222])
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` 
value: FromUtf8Error { bytes: [11, 222], error: Utf8Error { valid_up_to: 1, error_len: None } }', 
src/libcore/result.rs:1009:5
```

Python:
```
>>> bytearray([11,222])
bytearray(b'\x0b\xde')
```
