udemy-dl v1.0

Features:

• Added proper session management.
• Restructure code to make it bit nicer.
• Added proper logging for errors and warning which fixes (#477).
• Added support to download multiple courses from file.
• Added support to download by default just EN subtitle. (could use --sub-lang to download others)
• Added switch to keep WebVTT subtitles (option: --keep-vtt).
• Added support to fetch/skip HLS streams such as 1080p etc. (option to skip --skip-hls).
• Removed --names, --save switches.
• Removed --cache switch as proper session management is added.
• Removed --unsafe switch now unicode characters are handled properly in code.
• Added support to download/skip all available assets for a video (options: --assets-only, --skip-assets).
• Removed support for python 2 now only works with python 3