Updated resiliency gate script to consistently pass all gate stages,
using ubuntu bionic image for node deployment.
- Updated developer-onbording.rst with information on how to configure
and run the resilency gate behind corporate proxy.
- Updated the gate scripts to use the proxy configuration.
- Updated up.sh to pull the hyperkube image as cache, to speed up and
stabalize the initial kublet deployment of kubernetes cluster services.
- Updated and added sleeps and retries in some of gate stages and
scripts to avoid gate failures due to transient environment issues.
- Updated the ubuntu base image for node deployments from xenial to\
bionic base image.
- Added code in treadown-nodes stage to manually remove the etcd
members: kubernetes and calico, since they still remain listed as
etcd members on genesis node, even after genesis is torn down.
Change-Id: Ia11d66ab30ac7a07626d4f1d02a6da48155f862d