Heat rally scenario tests

This patch contains next main changes:
 - two scenarios for heat project ("create_and_list_stack",
   "create_and_delete_stack").
 - three atomic action for heat project ("stack-list" , "stack-create",
   "stack-delete").
 - two task samples how to use new scenarios.
 - a little changes in utils for supporting heat stack_status property.

Change-Id: Ice2bd4dc2fcefb7351df69dd8463abc6f8d4fd24