Sahara: add API tests for job binaries

* create/list/get/delete API tests for job binaries in Swift
  and in Sahara database were added
* "test_job_binary_get_data" test was added

Partially implements: blueprint savanna-api-tests

Change-Id: I0f2fcb79b469ad291fb0d9d3acba2fbfbfd7da27
Avoid snapshotting from compute authorization test

The compute authorization API tests currently rely on the creation of an image
via an instance snapshot.  Not all compute drivers support this and the tests
do not actually require the image to be a snapshot.  Instead, create a dummy
image in Glance directly to avoid making auth tests dependent on a hypervisor
feature.

Change-Id: I83a0fe12b1077ea87e402ec9897931631fa9cbf6
Closes-bug: #1331138
Missing node driver interface validation API

This patch implements missing API test for node validation.

There are three categories of driver interfaces:

- `Core` interfaces provide the essential functionality for Ironic
   within OpenStack, and may be depended upon by other services.
   All drivers must implement these interfaces. Presently, the Core
   interfaces are "power" and "deploy".
- `Standard` interfaces provide functionality beyond the needs of
  OpenStack, but which has been standardized across all drivers and
  becomes part of Ironic's API.
  If a driver implements this interface, it must adhere to the standard.
  This is presented to encourage vendors to work together with the
  Ironic project and implement common features in a consistent way,
  thus reducing the burden on consumers of the API.
  Presently, the Standard interfaces are rescue and console.
- The `Vendor` interface allows an exemption to the API contract when
  a vendor wishes to expose unique functionality provided by their
  hardware and is unable to do so within the core or standard interfaces.
  In this case, Ironic will merely relay the message from the API service
  to the appropriate driver.

As all drivers must implement core interfaces, I am checking only
core interfaces for response body validation.

part of blueprint: missing-baremetal-api-test

Change-Id: Ib6e81c875d55fb0c86dbb0de1c9a8337831196cc
Fix race condition in flavor tests

* Flavor tests (admin) create and delete flavors globally, This causes race
  condition for Flavor list tests where the list test is using the
  currently created flavors for further operations

Use locally created flavor reference in Flavor list tests

Change-Id: Id557a58008cf42e94524b061acaad9bb89f42ec7
Closes-Bug: #1267949
Merge "Sahara: add API tests for job binaries"
Merge "Avoid snapshotting from compute authorization test"
Merge "Missing node driver interface validation API"
Merge "Fix race condition in flavor tests"