Update to Discord.js v12.3.1

[IgorKowalczyk]

Changes:

+ Add new commands (eg. giveaway, moderation, image manipulation, music and even more!)
+ Update all files to Discord.js v12
+ Fix command handler
+ Update server logs
+ Fix all known bugs
+ Add web dashboard (Build on Express.js)
+ Fix the dashboard on heroku and other hosting platforms
- Remove not-used dependencies
- Remove old commands
- Remove old dashboard (Builded with Jekyll)

[IgorKowalczyk]

Merged and everything looks fine.

I spent a lot of time working on this pull-request, I had the worst time in my life, but during the hard work I met some great people.
Without them this pull-request would not have been completed, here are those people:

• @Joao-Victor-Liporini (Bug fixes, command-handler improvements, testing, new features)
• @dhvitOP (Music commands)

[dhvitOP]

;)