tether should update (instead of appending) containerName in /etc/hosts after changing the VM name in guestinfo

[chengwang86]

VIC version:

0.8

Deployment details:

What was the vic-machine create command used to deploy the VCH?
bin/vic-machine-linux create --name=vch-1 --target=root:pwd@192.168.60.162 --thumbprint=... --debug 1 --no-tlsverify --no-tls

Steps to reproduce:

1.	docker run –it –name=t1 busybox
2.	govc vm.change -vm t1* -e guestinfo.vice./common/name=t2
3.	docker stop t1
4.	docker start containerID_of_t1
5.	docker attach containerID_of_t1

Actual behavior:

vi /etc/hosts
127.0.1.1 t1 cb4acd2807e0 t2

Expected behavior:

vi /etc/hosts
127.0.1.1 cb4acd2807e0 t2

[chengwang86]

By this PR #4134, we have removed containerName from /etc/hosts. So this issue does not exist anymore.