serde_hjson::from_slice panics on decoding invalid utf8

[alexanderkjall]

Hi

I found that the from_slice function panics if the input isn't a valid utf8 string instead of returning an error value.

Can be reproduced with this unit test:

#[cfg(test)]
mod test {
    use crate::{Map,Value};
    use crate::error::Result;

    #[test]
    pub fn invalid_utf8() {
        let data: Vec<u8> = vec![155];

        let mut sample: Result<Map<String, Value>> = crate::from_slice(&data);
    }
}