Remove redundant checks of stack status

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
diff --git a/common/test.py b/common/test.py
index 2868d0f..a7aa039 100644
--- a/common/test.py
+++ b/common/test.py
@@ -352,7 +352,8 @@
 
     def stack_create(self, stack_name=None, template=None, files=None,
                      parameters=None, environment=None,
-                     expected_status='CREATE_COMPLETE', disable_rollback=True):
+                     expected_status='CREATE_COMPLETE', disable_rollback=True,
+                     enable_cleanup=True):
         name = stack_name or self._stack_rand_name()
         templ = template or self.template
         templ_files = files or {}
@@ -366,7 +367,7 @@
             parameters=params,
             environment=env
         )
-        if expected_status not in ['ROLLBACK_COMPLETE']:
+        if expected_status not in ['ROLLBACK_COMPLETE'] and enable_cleanup:
             self.addCleanup(self.client.stacks.delete, name)
 
         stack = self.client.stacks.get(name)