Removes duplicate options registration in registry clients

Fixes bug #1204359

Change-Id: I5b8bd9e4465d9fe70e9311474bc2b00d9afcf046
Remove unused import

Remove unused import in tests.functional.store modules to make codes
cleaner.

Change-Id: I07a66d0ba7c0f0233d0d03310d83b33f0b92bbe9
emit warning while running flake8 without virtual env

run_tests.sh -N -p

it will call the flake8 installed on your host to detect PEP8, and
the flake8 plugin "OpenStack hacking" may not installed on your
host, so this command may not detect the OpenStack Style Commandment
supplied by hacking(e.g H202).

run_tests.sh -p
it will call the flake8 from virtual env, flake8 plugin "OpenStack
hacking" installed in virtual env will be triggered.

The result from "run_tests.sh -p" should be trusted, and jenkins uses
virtual env to run flake8 too.

When "-N" is enabled, emit warning to stderr to remind user.

Bug #1215396

Change-Id: Iac6be532b7b9bb911b745712712d1be363e8ff01
Fix typo in IMAGE_META_HEADERS

x-image-meta-deleted-at replaced with x-image-meta-deleted_at
This prevents a problem when running the add_image method.

The bug was entered as part of the following commit:
c3e58bd943ccb4e1457914c3c2b5366bd0afee5a

Closes-Bug:#1220067
Change-Id: I6d1624a00e89721f5c9af969e191951fdcb2ee43
Publish recent api changes as v2.2

Throughout the Havana development cycle, we have added several
features to the v2 api, without breaking backwards compatibility.
So this change bumps up our minor version number.

Change-Id: If0e5ffe117200fbfb967c8c95a63608f12dbba58
Merge "Publish recent api changes as v2.2"
Merge "Removes duplicate options registration in registry clients"
Merge "Fix typo in IMAGE_META_HEADERS"
Merge "emit warning while running flake8 without virtual env"
Merge "Remove unused import"