* update image api *os.File to io.Reader
* update code style
* add reader test
* supplementary reader test
* update the reader in the form builder test
* add commnet
* update comment
* update code style
* Implement optional io.Reader in AudioRequest (#303) (#265)
* Fix err shadowing
* Add test to cover AudioRequest io.Reader usage
* Add additional test cases to cover AudioRequest io.Reader usage
* Add test to cover opening the file specified in an AudioRequest