Commit Ie639179c5bbbaca4de62b42b368830afcfd8f7ac introduced 'visibility'
and 'protected' params. These params should be used only with
v3.1 microversion. Also these changes break current v2 users.

This patch fixes these issues.

Closes-Bug: #1584056
Change-Id: I0574631791c475bbefdb6e7d1647a20d0759df64

Return appropriate wrapper classes with request_ids attribute from
base class.

Note:
In cinderclient/base.py->_update method will return None for
qos_specs->unset_keys method and for all other cases it returns body
of type dict. At few places, wherever the _update method is called,
it converts the return value back to the resource class and in all
other cases the same return value is returned back to the caller.
It's not possible to return request_ids with None so for all cases
object of DictWithMeta will be returned from this method. Second
approach would be to return (resp, body) tuple from _update method
and wherever this method is called, return the appropriate object.
These changes will affect v1 version and since v1 is already
deprecated the above approach sounds logical.

This change is required to return 'request_id' from client to log
request_id mappings of cross projects.

Change-Id: If73c47ae2c99dea2a0b1f25771f081bb4bbc26f1
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