Adds test_update_all_metadata_field_not_included negative test

Adds test_update_all_metadata_field_not_included negative test
which checks a BadRequest is returned when attempting to
set the server metadata and not include the metadata field

Collapses all of the negative tests into one testcase as they
should not have any side effects and it will slightly reduce
setup overhead.

Change-Id: Iab221d23e896fb22bbe351bb20c0378ebaa60add
Closes-Bug: 1131536
Orchestration autoscaling improve status polling

This change includes the following improvements to the
autoscaling test:
- On stack create status timeout, override the error status so
  that FAILED stacks fail fast
- Improve the error message in assertScale
- Delete the stack at the end of the scenario, and confirm the delete
  succeeded

Change-Id: Ia220e3a2b422472ac7c6d29f9a5a61bd7c4987c3
add some negative tests for tenant

making a separate test_tenant_negative.py,and move the exist negative
tests over to it,and add some negative tests for in it.

- test_update_non_existent_tenant
- test_tenant_update_by_unauthorized_user
- test_tenant_update_request_without_token

Change-Id: Id0d15d312c96a3f8a244d5e08414623e3c15013a
Fix to use proper random values

In several tests, they need int values but use rand_name().
Especially, test_security_group_rules.py has a potentially bug.
And, when we will change the rand_name() to return string value, the
errors will occur in others.
So this commit fixes it and belows:
 * just import the module instead of importing the function
 * minor comment typo

Change-Id: Ic957c741b9ad3631d726dc6cfb5ecb9e0077a884
Merge "Adds test_update_all_metadata_field_not_included negative test"
Merge "add some negative tests for tenant"
Merge "Orchestration autoscaling improve status polling"
Merge "Fix to use proper random values"