Is there a reason for [InsertAsync](https://github.com/StackExchange/dapper-dot-net/blob/master/Dapper.Contrib/SqlMapperExtensions.cs#L290) returning `int` while [Insert](https://github.com/StackExchange/dapper-dot-net/blob/master/Dapper.Contrib/SqlMapperExtensions.Async.cs#L124) returns a `long`? 