The main methods create/update/delete in HeatIntegrationTest class
already contains _wait_for_stack_status, so we can remove duplicate
checks in tests.
Also was added paramter enable_cleanup for stack_create method, which
allows to disable CleanUp method in tests, where we delete stack
manually.
Change-Id: I41b546d648656676ec9bc3b38940eac68f9a848d