Add initial Microsoft Teams support

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

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

@@ -0,0 +1,25 @@
+// Code generated by msgraph-generate.go DO NOT EDIT.
+
+package msgraph
+
+// CallDirection undocumented
+type CallDirection int
+
+const (
+	// CallDirectionVIncoming undocumented
+	CallDirectionVIncoming CallDirection = 0
+	// CallDirectionVOutgoing undocumented
+	CallDirectionVOutgoing CallDirection = 1
+)
+
+// CallDirectionPIncoming returns a pointer to CallDirectionVIncoming
+func CallDirectionPIncoming() *CallDirection {
+	v := CallDirectionVIncoming
+	return &v
+}
+
+// CallDirectionPOutgoing returns a pointer to CallDirectionVOutgoing
+func CallDirectionPOutgoing() *CallDirection {
+	v := CallDirectionVOutgoing
+	return &v
+}