Verify the response attributes of 'update-aggregate' API

This patch verifies the response attributes of 'update-aggregate'.
The response body of v2 and v3 API has the same format:
{
    "aggregate": {
        "availability_zone": "nova2",
        "created_at": "2013-08-18T12:17:56.259751",
        "deleted": false,
        "deleted_at": null,
        "hosts": [],
        "id": 1,
        "metadata": {
            "availability_zone": "nova2"
        },
        "name": "newname",
        "updated_at": "2013-08-18T12:17:56.286720"
    }
}
This patch also fixes a typo bug of the schema.

Partially implements blueprint nova-api-attribute-test

Change-Id: I89547d8069aae9d2ad0b4cd081843865f42bc4e7
Skip more pause tests if pause is not available

There are several compute API tests that attempt to pause a server but
should be skipped if the pause feature is not enabled.

Note that there are some negative tests which call the pause API but on
invalid server states, i.e. non-existent server, unpausing a server
that's not paused, etc, but those shouldn't get down to the virt driver
so we don't need to skip them since they should fail in the Nova API
service, not in the compute service.

Related-Bug: #1296858

Change-Id: I6f74c17af2c7540f913b71350770be7f004769a9
Verify delete server attributes of Nova API

This patch adds the JSON schema for Nova V2 & V3 delete server
API response and validate the response with added JSON schema
to block the backward incompatibility change in the future.

Response status of delete APIs is 204

Partially implements blueprint nova-api-attribute-test

Change-Id: Ibcc8d7067531f41a55c7ced93911f34e87e16f0e
Merge "Skip more pause tests if pause is not available"
Merge "Verify the response attributes of 'update-aggregate' API"
Merge "Verify delete server attributes of Nova API"