Add Slack support

vendor/github.com/nlopes/slack/websocket_teams.go

@@ -0,0 +1,33 @@
+package slack
+
+// TeamJoinEvent represents the Team join event
+type TeamJoinEvent struct {
+	Type string `json:"type"`
+	User User   `json:"user"`
+}
+
+// TeamRenameEvent represents the Team rename event
+type TeamRenameEvent struct {
+	Type           string `json:"type"`
+	Name           string `json:"name,omitempty"`
+	EventTimestamp string `json:"event_ts,omitempty"`
+}
+
+// TeamPrefChangeEvent represents the Team preference change event
+type TeamPrefChangeEvent struct {
+	Type  string   `json:"type"`
+	Name  string   `json:"name,omitempty"`
+	Value []string `json:"value,omitempty"`
+}
+
+// TeamDomainChangeEvent represents the Team domain change event
+type TeamDomainChangeEvent struct {
+	Type   string `json:"type"`
+	URL    string `json:"url"`
+	Domain string `json:"domain"`
+}
+
+// TeamMigrationStartedEvent represents the Team migration started event
+type TeamMigrationStartedEvent struct {
+	Type string `json:"type"`
+}