Update release notes for v1.1.16
Update release notes for v1.1.16

0312birdzhang/alerta,mrkeng/alerta,guardian/alerta,skob/alerta,mrkeng/alerta,skob/alerta,0312birdzhang/alerta,0312birdzhang/alerta,mrkeng/alerta,guardian/alerta,skob/alerta,mrkeng/alerta,skob/alerta,guardian/alerta,guardian/alerta