Support snake case in column headers

[tbshillcdr]

When a column headers are in snake case the words blend together without proper Capitalization.

type ChargeRecord struct {
        Businessentityid                  string `csv:"business_entity_id"`
        Sourcepatientlastname             string `csv:"source_patient_last_name"`
        Sourcepatientfirstname            string `csv:"source_patient_first_name"`
}