tests should only run when applicable for adv-sg zone in such env

##### ISSUE TYPE

* Documentation Report
* testing/CI

##### COMPONENT NAME

~~~
marvin
~~~

##### CLOUDSTACK VERSION

~~~
4.18
~~~

##### CONFIGURATION

~~~
advanced zone with security groups.
~~~

##### OS / ENVIRONMENT

##### SUMMARY

when an advanced zone with security groups is used to test for regressions, a lot of errors occur.
an example
```
ERROR: test suite for
----------------------------------------------------------------------
Traceback (most recent call last):
File "/usr/local/lib/python3.6/site-packages/nose/suite.py", line 210, in run
self.setUp()
File "/usr/local/lib/python3.6/site-packages/nose/suite.py", line 293, in setUp
self.setupContext(ancestor)
File "/usr/local/lib/python3.6/site-packages/nose/suite.py", line 316, in setupContext
try_run(context, names)
File "/usr/local/lib/python3.6/site-packages/nose/util.py", line 471, in try_run
return func()
File "/marvin/tests/smoke/test_router_dns.py", line 92, in setUpClass
zoneid=cls.zone.id)
File "/usr/local/lib/python3.6/site-packages/marvin/lib/base.py", line 3562, in create
return Network(apiclient.createNetwork(cmd).__dict__)
File "/usr/local/lib/python3.6/site-packages/marvin/cloudstackAPI/cloudstackAPIClient.py", line 2981, in createNetwork
response = self.connection.marvinRequest(command, response_type=response, method=method)
File "/usr/local/lib/python3.6/site-packages/marvin/cloudstackConnection.py", line 381, in marvinRequest
raise e
File "/usr/local/lib/python3.6/site-packages/marvin/cloudstackConnection.py", line 376, in marvinRequest
raise self.__lastError
File "/usr/local/lib/python3.6/site-packages/marvin/cloudstackConnection.py", line 310, in __parseAndGetResponse
response_cls)
File "/usr/local/lib/python3.6/site-packages/marvin/jsonHelper.py", line 155, in getResultObj
raise cloudstackException.CloudstackAPIException(respname, errMsg)
marvin.cloudstackException.CloudstackAPIException: Execute cmd: createnetwork failed, due to: errorCode: 431, errorText:Only shared guest network can be created in security group enabled zone
```

this is not necessary as we know beforehand that these tests will fail.
Tests need to be properly tagged to not run in these environments.

##### STEPS TO REPRODUCE

~~~

~~~

##### EXPECTED RESULTS

~~~
test will not run
~~~

##### ACTUAL RESULTS

~~~
test runs and fails
~~~

marvin/tests/smoke/test_router_dns.py と、レポートに示されている TestRouterDns のセットアップから始め、その後、セキュリティグループを使用する高度なゾーンで失敗する他の回帰テストを調査します。この環境では適用できないテストが実行されて失敗するのではなくスキップされれば完了です。影響を受けるテストスイートで動作を確認してください。

索引モデルが issue の本文から書いたものです。