Add quota_set delete test for Nova v3 API

This patch adds tests for quota_set API.

Partially implements blueprint nova-v3-api-tests

Change-Id: If89b8fd4afbe496a4609694123a480e7f045127d
Convert fake_config class to use config fixture

This commit changes the fake_config object used in the unit tests to
use the config fixture and use the real config defaults by registering
the config options and using the oslo config set_default method to
override the defaults when needed for testing. This will enable reusing
the tempest defaults in most places which should save effort duplicating
defaults in the fake object.

Partially Implements bp unit-tests

Change-Id: Ib9ee8e68f7000bfbcd3cd1c94cca103a3286ec77
Add unit basic unit tests for tenant_isolation

This commit adds some basic unit test coverage for the tenant isolation
code. It doesn't provide complete coverage yet, but to avoid having
a giant patch this is the first chunk.

Partially implements bp unit-tests

Change-Id: Ic7d5368a4c0b8c2eeb61a73481f630ba04ee70b0
Add network credential unit testing

This commit adds some of the missing coverage from the isolated
credentials unit tests. This also adds the unit tests for the alt
user/tenant.

Partially implements bp unit-tests

Change-Id: Id5e7ba3e8d2b74f20651d522efa9856886c64de7
Merge "Convert fake_config class to use config fixture"
Merge "Add unit basic unit tests for tenant_isolation"
Merge "Add network credential unit testing"
Merge "Add quota_set delete test for Nova v3 API"
Merge branch 'master' of https://github.com/openstack/tempest