Enforce ordering of imports with H306.

For tests, this is mostly done by grouping test
imports after other cinderclient imports.

Change-Id: Ie40fda014d1aedb057e5b4ea1f27f999c84e6373

Added request_ids attribute to resource object for all the
cgsnapshots, consistencygroups, qos_specs, quota_classes,
quotas and services APIs by updating following APIs:

cgsnapshots: delete, update
consistencygroups: delete, update, create
qos_specs: delete, associate, disassociate, disassociate_all
quota_classes: update
quotas: update
services: enable, disable, disable_log_reason

These changes are required to return 'request_id' from client to
log request_id mappings of cross projects.

For more details on how request_id will be returned to the caller,
please refer to the approved blueprint [1] discussed with the
cross-project team.
[1] http://specs.openstack.org/openstack/openstack-specs/specs/return-request-id.html

DocImpact
'request-ids' will be returned as an attribute with response object.
User can access it using 'res.request_ids' where 'res' is a
response object.

Change-Id: I7b399512fcec9ecd31938656deb60e325bb76ad4
Partial-Implements: blueprint return-request-id-to-caller

This is the first step of moving functional testing
into the project tree.  This change just moves
all of the unit tests to be under a dedicated tests/unit
directory.

Follow up patches will add the functional directory and
start moving tempest CLI tests there.

Change-Id: I9dc0b8f761676c1b3bbdeb03e2f44b35f75c693e