v1.2.1 release

Change-Id: I42dc044fa57852d67299c82a5adc40d48887adcd

upgrade to 1.2.0

upgrade to 1.1.9

update to 1.1.8

upgrade to 1.1.7

upgrade to 1.1.6

upgrade pomelo-rpc to 0.4.7

upgrade to 1.1.4

bump version to 0.6.21

Change-Id: I44993deba80c4a28a6985a6bd35a9c9ea5135fc4

bump version to 1.1.1

Change-Id: I780870f527614bdc687c50551e006ff3254136cf