Added Presences field for GuildMembersChunk (#755)

events.go

@@ -139,8 +139,9 @@ type GuildEmojisUpdate struct {
 
 // A GuildMembersChunk is the data for a GuildMembersChunk event.
 type GuildMembersChunk struct {
-	GuildID string    `json:"guild_id"`
-	Members []*Member `json:"members"`
+	GuildID   string      `json:"guild_id"`
+	Members   []*Member   `json:"members"`
+	Presences []*Presence `json:"presences,omitempty"`
 }
 
 // GuildIntegrationsUpdate is the data for a GuildIntegrationsUpdate event.