fails:Net::FTP#delete sends the DELE command with the passed filename to the server
fails:Net::FTP#delete raises a Net::FTPTempError when the response code is 450
fails:Net::FTP#delete raises a Net::FTPPermError when the response code is 550
fails:Net::FTP#delete raises a Net::FTPPermError when the response code is 500
fails:Net::FTP#delete raises a Net::FTPPermError when the response code is 501
fails:Net::FTP#delete raises a Net::FTPPermError when the response code is 502
fails:Net::FTP#delete raises a Net::FTPTempError when the response code is 421
fails:Net::FTP#delete raises a Net::FTPPermError when the response code is 530
