CreateBucket won't work without LocationConstraint for non-default regions

[ryanbutterfield]

For S3, I found I couldn't use CreateBucket wihout also providing a CreateBucketConfiguration with a LocationConstraint if the region wasn't the default region of us-east-1.

eg.

let action = CreateBucket::new(&self.bucket, &self.credentials);

let body = vec![
    r#"<CreateBucketConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/">"#,
    &format!(
        "<LocationConstraint>{}</LocationConstraint>",
        self.bucket.region()
    ),
    "</CreateBucketConfiguration>",
]
.join("");

self.client
    .put(action.sign(ONE_HOUR))
    .body(Body::from(body))
    .send()?
    .error_for_status()?;

Recommend adding a .body() function to CreateBucket, similar to how CompleteMultipartUpload provides a .body().

Ps. Thank you for this library. Apart from this, it works perfectly, and was the first non-async S3 library I could get working.