Function avocado::bsn::serialize_document

pub fn serialize_document<T: Serialize>(value: &T) -> Result<Document>

Creates a BSON Document out of a serializable value. TODO(H2CO3): validate that the value doesn't contain integers not expressible by i64, because the BSON library just casts everything, and overlfowing positive values may end up as negatives in the BSON.