Check if newly created Openstack CLoud Server RHEL instance is activated or no

* Work in progress
* Modified the test fixture in order to use the newly created get image by search name behavior
* Added reponse check for create key client call
* Changed raised failure to Exception in case servers are not created
* Removing not needed class variable
* CHeck to see if there are any images returned

Change-Id: Iaa355fc4a9e33edf7fbc019ed610193b3f2a416d
Merge "Check if newly created Openstack CLoud Server RHEL instance is activated or no"