Add unit tests for negative test framework

Add basic test cases for generate_json and negative auto test.

Partially-implements: bp negative-tests
Change-Id: I52d376689c0eca0e732ec8a506039b4ef0e326fe
Multiversion authentication part2

Address last comments from part1:
- replace auth_data[0] with get_token()
- add token property to rest_client
- Remove comment about planned changes from config.py

Partially implements: bp multi-keystone-api-version-tests

Change-Id: Ia54cd3d824e44dd99d9226d4c0c6d6861d8c12ae
Fix client usage in multibackend volume test

This commit fixes the client usage in the multibackend volume api
tests. There was no reason for the test to initialize new instances
of the clients directly. Firstly this wasn't tenant isolation safe
and secondly the clients are already instantiated with admin credentials
in the base admin class setUpClass(). This commit just switches the
tests to use those clients instead.

Change-Id: Ifc986b82dcfe872ff1b25babd78ab90e996d5c12
Use service catalog_type when getting the heat/glance clients

The 'orchestration' service_type is currently hard-coded when getting
the heat client but there is an orchestration.catalog_type config option
available, so use that rather than hard-code the value.

The same is true for the _get_image_client method and
CONF.image.catalog_type option, so fix that as well.

Change-Id: I6b4ba44619b9ddf99f063bc28c7c4bbae67408a8
Remove tox locale overrides

* tox.ini: The LANG, LANGUAGE and LC_ALL environment overrides were
introduced originally during the testr migration in an attempt to be
conservative about the possibility that locale settings in the
calling environment could cause consistency problems for test runs.
In actuality, this should be unnecessary and any place where it does
cause issues ought to be considered an actual bug. Also, having
these in the configuration actively causes older pip to have
problems with non-ASCII content in some package metadata files under
Python 3, so drop it now.

Change-Id: Iaf6006fd20031d423bc6ce47cfc604fe936ba5c2
Closes-Bug: #1277495
Rename images variable in TempestConfigPrivate

The images variable in TempestConfigPrivate is the wrong name since the
group in tempest.conf is actually 'image' so rename it to match the
config file along with any usage of the variable.

Change-Id: I3144734942151c0e807c53e329709abcb9438167
Fix test_create_list_delete_volume_transfer without tenant isolation

The test was making an assumption that there would be exactly one volume
transfer listed which is not the case when running without tenant
isolation. Note the test before it asserts the listed transfers are
greater than or equal to one so it works without tenant isolation.

The reason this doesn't work in the single-threaded case is probably
because another test is not cleaning up properly so there is a leak
somewhere, therefore this is a partial fix until the leak is resolved.

Partial-Bug: #1277788

Change-Id: I68b2df2d7792da7c3a9ce001af41cd199ccdbc13
Merge "Add unit tests for negative test framework"
Merge "Use service catalog_type when getting the heat/glance clients"
Merge "Multiversion authentication part2"
Merge "Remove tox locale overrides"
Merge "Fix client usage in multibackend volume test"
Merge "Rename images variable in TempestConfigPrivate"
Merge "Fix test_create_list_delete_volume_transfer without tenant isolation"
Merge branch 'master' of https://github.com/openstack/tempest