Please add Range::headers() -> Vec<String>

[lucatrv]

It is often required to get the first row values of a range deserialized to strings (which are the range headers), so IMHO it would be useful to add a specific helping method headers to Range, which would be equivalent to calling rows().next() and then converting to String. The csv crate has a similar method, see tutoral and documentation.
To convert each DataType value to String, the headers method should call ToString::to_string.