coinbase.go
func (c Client) CompleteRequest(id string) (*transactionConfirmation, error) {
	return c.transactionRequest("PUT", id+"/complete_request", nil)
}
func (c Client) CompleteRequest(id string) (*transactionConfirmation, error) {
	return c.transactionRequest("PUT", id+"/complete_request", nil)
}
// CompleteRequest completes a money request referenced by id