Zuul v2 uses 'jenkins' as user, but Zuul v3 uses 'zuul'.
Using $USER solves it for both cases.

Change-Id: I7bd4c3d5a0acc2c73557a65dcc274a97f16bfd07

Enforce ordering of imports with H306.

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

Change-Id: Ie40fda014d1aedb057e5b4ea1f27f999c84e6373

The show command currently just dumps the entire attachments
dictionary into the output which is a real mess and completely
screws up the displayed output (shell command).

There's really no reason to do this, we can just give the
attachment ID's and then when you're on the newer versions
you can do an attachment-show for all the crazy details if
you want.  Keep in mind that the list command already shows
the server-id we're attached too, but that might also be
nice from the show command rather than jumping through
multiple commands.  To try and accomodate various use cases
we'll also add an "attached_servers" field to the show command,
but you'll have to coorelate manually from there.

Change-Id: I45ac49d8d9a185c52727c5bc24a6a1323be83689
Closes-Bug: #1494941

Gives more time to wait resource's status to change
in functional testcases and adds default interval
to reduce query amount.

Change-Id: I2a29a2d04836fd1261d45e404341bb1aa657417b

Use 'six.text_type' to wrap defined string value.

Change-Id: I229d58595494f59f03538be79de42f2e8007f442
Closes-Bug: #1697401

The behaviour of PY3's standard lib 'argparse'
differs from PY2's.

```
cinder extend 2
usage: cinder extend <volume> <new_size>
error: too few arguments
Try 'cinder help extend' for more information.

cinder extend 3
usage: cinder extend <volume> <new_size>
error: the following arguments are required: <new_size>
Try 'cinder help extend' for more information.

```
This could lead to the partly failure of functional testcase,
fix it.

Change-Id: I59e9ae149af0b4294b09a94a52a4bc86a1d90f2b
Closes-Bug: #1697428