Update copyright headers

authorizer/authorizer_test.go

authorizer/endpoint.go

authorizer/handler.go

client/client.go

client/gateway.go

client/gateway_test.go

client/mockServer_test.go

client/notificationBot.go

client/notificationBot_test.go

client/registration.go

client/registration_test.go

client/ud.go

client/ud_test.go

clientregistrar/clientregistrar_test.go

clientregistrar/endpoint.go

clientregistrar/handler.go

gateway/batch.go

gateway/batch_test.go

gateway/broadcast.go

gateway/broadcast_test.go