Added instancespage based on the new regions.
test_instances checks the instance createion and deletion.
Few other modifications I've made:
* forms:
- removed "div >" from checkbox locator, to identify "default" checkbox in
"launch_instance->Access & Security ->default"
*horizon.conf
- Added [launch_instances] to include instances attributes from config file
*config
- Added InstancesGroup to include [launch_instances] from horizon.conf
Partially implements blueprint: integration-tests-hardening
Change-Id: I7d58a970fd36ff86021f3f050c5d01586a26599c