Kubernetes quick start yaml needs update to docker repo location

[myechuri]

Yaml file for Contrail single step CNI install on ubuntu attempts to pull images from ci-repo.englab.juniper.net:5010 repo which is inaccessible from outside of Juniper:

root@ip-172-20-51-40:~# docker -D pull ci-repo.englab.juniper.net:5010/contrail-external-zookeeper
Using default tag: latest
Pulling repository ci-repo.englab.juniper.net:5010/contrail-external-zookeeper
Error while pulling image: Get http://ci-repo.englab.juniper.net:5010/v1/repositories/contrail-external-zookeeper/images: dial tcp: lookup ci-repo.englab.juniper.net on 172.20.0.2:53: no such host
root@ip-172-20-51-40:~#

$ nslookup ci-repo.englab.juniper.net
Server:		2001:558:feed::1
Address:	2001:558:feed::1#53

** server can't find ci-repo.englab.juniper.net: NXDOMAIN

All of the container images listed in the yaml file are available from default docker hub under opencontrailnightly org. So, replaced ci-repo.englab.juniper.net:5010 with opencontrailnightly in yaml file:

K8S_MASTER_IP=x.x.x.x;CONTRAIL_REPO=opencontrailnightly; CONTRAIL_RELEASE="latest"; mkdir -pm 777 /var/lib/contrail/kafka-logs; curl https://raw.githubusercontent.com/Juniper/contrail-kubernetes-docs/master/install/kubernetes/templates/contrail-single-step-cni-install-ubuntu.yaml | sed "s/{{ K8S_MASTER_IP }}/$K8S_MASTER_IP/g; s/{{ CONTRAIL_REPO }}/$CONTRAIL_REPO/g; s/{{ CONTRAIL_RELEASE }}/$CONTRAIL_RELEASE/g" | kubectl apply -f -

After the update, k8s was able to pull images for all of the objects in the manifest successfully.

Happy to submit PR for README if granted access. Thanks!