restapi structure is different then expected

[fryguy503]

It looks like https://github.com/bwmarrin/discordgo/blob/master/restapi.go#L395 has been updated and the newer structure is looking for:

// UserGuilds returns an array of UserGuild structures for all guilds.
// limit : The number guilds that can be returned. (max 100)
// beforeID : If provided all guilds returned will be before given ID.
// afterID : If provided all guilds returned will be after given ID.

Fails build due to this requirement. Temporarily rolling back the UserGuilds() function resolves the issue locally.