Users/modnaruser/audio codec flag

[ModnarUser]

Added cli flag for setting audio codec (flac/mp3) because I was finding myself converting everything to mp3 anyway ;)

[ModnarUser]

successfully tested with a bunch of songs and the following invocations:

• ./spotrec.py -o ./my_song_dir --skip-intro --audio-codec mp3
• ./spotrec.py -o ./my_song_dir --skip-intro
• ./spotrec.py -o ./my_song_dir --skip-intro --audio-codec flac