* Inject target-cluster-ca as sceret
* Create kubeconfig using gate scripts with both ephemeral and
target clusters.
* With both contexts predefined in kubeconfig,
just switch/use context in gate scripts as required.
* Removed the use of airshipctl import from gate script
Change-Id: I5a9a56db71f0a80d9b35144eacbdd980c13c9ffb
Relates-To: #329
Closes: #329