Allow bot to join voice chats and play cinematic music

[M-Davies]

Similar to what Rythm does, I'd like the ability for this bot to join a voice chat with a simple command and start playing cinematic music appropriate to the situation. I'm thinking something along the lines of:

1. A new command (Maybe ?play dungeon | forest | city) that will force the bot to join the voice channel of the executer and play ambient music of the category specified
2. Other music commands that will stop the music, skip the current song or kick the bot out of the voice chat