Add Discord implementation
This adds the ability to connect linkbait to Discord.
Use -s discord
to select the discord service. A token can be acquired at https://discordapp.com/developers/applications/me
You then need to take the client ID from the page and open this link to add it to your guild: https://discordapp.com/oauth2/authorize?client_id=<client_id_here>&scope=bot&permissions=0