Release v1.2.0

Improvements:

• Removed the MusicState Enum from music.py (#20)
• Playlist can now be handled asynchronously to avoid racing conditions (#16)

New:

• Bot now has the command !permission <type> to display a permissions matrix that displays which roles / text channels are allowed for using the bot (#21)
• Bot now have the commands !role <id> ... and !text_channel <id> ... to dynamically adjust the bot configuration during runtime (#19)
• Bot now has the command !timeout <time> to dynamically adjust the bot configuration during runtime (#19)
• Bot now has the command !id <type> to display the IDs of roles / text channels to better work with !role and!text_channel ``` (#19)