Check reserve/unreserve fixed-ips APIs attributes

This patch adds the JSON schema for Nova V2 reserve & unreserve
fixed-ips APIs response and validate the response with added JSON
schema to block the backward incompatibility change in the future.

The response body of V2 reserve & unreserve fixed-ip API is below:

{
    "202 Accepted The request is accepted for processing."
}

Partially implements blueprint nova-api-attribute-test

Change-Id: Ic837fb3cdc34a79c25589a7263f54b96b6043680
Verify "get quotas detail" API response attributes

This patch adds checks whether a response of
Nova os-quota-sets get detail v3 API includes the attributes
to block the backward incompatibility change in the future.

The quotas response body of v3 API is the following:
{
    "quota_set": {
        "id": "30032cae7b864e5aad589c506fa83b70",
        "instances": {
            "reserved": 0,
            "limit": 10,
            "in_use": 0
        },
        "cores": {
            "reserved": 0,
            "limit": 20,
            "in_use": 0
        },
        "ram": {
            "reserved": 0,
            "limit": 51200,
            "in_use": 0
        },
        "floating_ips": {
            "reserved": 0,
            "limit": 10,
            "in_use": 0
        },
        "fixed_ips": {
            "reserved": 0,
            "limit": -1,
            "in_use": 0
        },
        "metadata_items": {
            "reserved": 0,
            "limit": 128,
            "in_use": 0
        },
        "key_pairs": {
            "reserved": 0,
            "limit": 100,
            "in_use": 0
        },
        "security_groups": {
            "reserved": 0,
            "limit": 10,
            "in_use": 0
        },
        "security_group_rules": {
            "reserved": 0,
            "limit": 20,
            "in_use": 0
        }
    }
}

Partially implements blueprint nova-api-attribute-test

Change-Id: I6600f834b031b6c832176f640b0b481d6af8a371
Merge "Check reserve/unreserve fixed-ips APIs attributes"
Merge "Verify "get quotas detail" API response attributes"
Merge branch 'master' of https://github.com/openstack/tempest