better resolution detection inside getInfo - support for audio only & other formats

thanks for the great lib! I just updated and found this small bug fix for non youtube videos that were returning an empty array because the regex was not detecting a row that contained the resolution.

reference for resolutions returned by youtube-dl: https://github.com/rg3/youtube-dl/blob/39f0a2a6b71c5d3cb2e2f8ef1bc3eeeaa6a96971/youtube_dl/YoutubeDL.py#L1178
should these changes be applied to `formatRegex` too?