Add initial Microsoft Teams support

Documentation on https://github.com/42wim/matterbridge/wiki/MS-Teams-setup

vendor/github.com/yaegashi/msgraph.go/beta/IdentitySetModel.go

@@ -0,0 +1,15 @@
+// Code generated by msgraph-generate.go DO NOT EDIT.
+
+package msgraph
+
+// IdentitySet undocumented
+type IdentitySet struct {
+	// Object is the base model of IdentitySet
+	Object
+	// Application undocumented
+	Application *Identity `json:"application,omitempty"`
+	// Device undocumented
+	Device *Identity `json:"device,omitempty"`
+	// User undocumented
+	User *Identity `json:"user,omitempty"`
+}