Clarify API extension description of Nova API

On Nova API, we can see two names for each API extension. The one is
"Name", the other is "Alias". The "Name" is represented with camelcase
and the "Alias" is done with characters and hyphens:

 $ nova list-extensions
 +--------------+-----------------------+------------------+---------+
 | Name         | Summary               | Alias            | Updated |
 +--------------+-----------------------+------------------+---------+
 | AdminActions | Enable admin-only ... | os-admin-actions | ...     |
 | Agents       | Agents support.       | os-agents        | ...     |
 | ConsoleOutput| Console log output... | os-console-output| ...     |
 | Consoles     | Interactive Console.. | os-consoles      | ...     |

In Tempest, we can select API extensions what we test and it should be
based on "Alias", because on Nova side we have been a lot stricter about
format/uniqueness for the alias which is seen as the canonical name.
This patch clarifies it.

Change-Id: I3e753c81182af83e01ad3a1f2eb9782c8abb6f50
Check create/get/delete V2 server_group attributes

This patch adds the JSON schema for Nova V2 create, get & delete
server_group APIs response and validate the response with added
JSON schema to block the backward incompatibility change in the future.

The response body of create & get server_group V2 APIs is same and given
below:

{
    "server_group": {
        "id": "5bbcc3c4-1da2-4437-a48a-66f15b1b13f9",
        "name": "test",
        "policies": ["anti-affinity"],
        "members": [],
        "metadata": {}
    }
}

Delete server_group API only return 204 response code.

Partially implements blueprint nova-api-attribute-test

Change-Id: I0447292553394877493fc264451559d9df14242f
Optimization and response status code update

In following test files response status code is not being checked -
1. test_api_discovery.py
2. test_chassis.py
3. test_nodes.py
4. test_ports.py

This patch adds checking for missing response status code in above.
Also it optimize codes of files.
Change-Id: I4bc5aa756508b533919c283ce18f641fec50b30e
add block_device_mapping to create_server params for nova clients

Change-Id: Ic931fab33b461b00a2155407bf307c692c7f18e6
Closes-Bug: #1327942
Remove the validate_driver_info test

This test is not exercising anything in the API, it's just looking at
some driver specific parameters, and so can be dropped.

Implements: blueprint add-node-instance-info
Change-Id: Icd14925058a388eba9fd2aa1b06b1db7f80f1327
Disable isolated_creds.net_resources on network scenarios

These tests creates their own network resources as part of the scenario.
isolated_creds network resources are redundant.

Change-Id: Iea047c48e9b50c9dcca4c73073056274594c42fb
Partial-Bug: 1263635
Merge "add block_device_mapping to create_server params for nova clients"
Merge "Optimization and response status code update"
Merge "Remove the validate_driver_info test"
Merge "Disable isolated_creds.net_resources on network scenarios"
Merge "Check create/get/delete V2 server_group attributes"
Merge "Clarify API extension description of Nova API"
Merge branch 'master' of https://github.com/openstack/tempest