Unicase::new(&str) != Unicase::from(&str), from impl ignores ASCII

[samadDotDev]

The following test fails since the from implementation doesn't check for ASCII vs Unicode encoding, and always maps to unicode even for ASCII strings.

#[cfg(test)]
mod tests {
    use unicase::UniCase;

    #[test]
    fn unicase_ascii() {
        let unicase = UniCase::new("Hello");
        assert!(unicase.is_ascii());

        let unicase: UniCase<&str> = UniCase::from("Hello");
        assert!(unicase.is_ascii());
    }
}

[seanmonstar]

Thanks for the report! Would you like to submit a PR fixing it?

[samadDotDev]

Thanks for the report! Would you like to submit a PR fixing it?

Sure thing!