changed media for media_data parameter on upload  (chunked) file request
changed media for media_data parameter on upload  (chunked) file request

according with https://dev.twitter.com/rest/reference/post/media/upload-chunked, the base64-encoded file should be passed on the media_data

rafasashi/twitteroauth,shakaran/twitteroauth,abraham/twitteroauth,aaron-goshine/twitteroauth