when support latest on docker plugin install

[arnolix]

Hi,
[root@dcos-slave01 rootfs]# docker plugin install contiv/v2plugin:1.2.1 xx xx xx xx....
Error response from daemon: manifest for contiv/v2plugin:1.2.1 not found

https://hub.docker.com/r/contiv/v2plugin/tags/ now support 1.1.9 , I very like this plugin, hope to support latest 1.2.1 , thx~!

Your Environment

• netctl version
• Orchestrator version (e.g. kubernetes, mesos, swarm):
• Operating System and version