Improve test/utils.py

Introduce new class into utils.py to keep glance api tests DRYer

Partially implements blueprint glance-tests-code-duplication

Change-Id: Ic77961fcc83806fd451afa1a0d230f09926ebfd9
Refactor glance/tests/unit/v2/test_registry_client.py

Remove code duplication from module

Partially implements blueprint glance-tests-code-duplication

Change-Id: Idf54d98d0982b7c64696056c87283eb92f1164b5
Code dedup in glance/tests/unit/v1/test_registry_api.py

Move duplicated fixture set-ups, requests and assertions to tests.utils.py

bp glance-tests-code-duplication

Change-Id: Ie0f13b5f5d5a242f24ac7cd6cc548ff09ebe6ba5
Fix typo in config string

Add a single space to change "isthis" to "is this".

Change-Id: I95a001f5025ef4c41467b363cdd3adf8258e8f10
Removed unsued import, HTTPError in v1/images.py.

Fixes bug 1235762

Change-Id: Ice5574f1f61d5064d73f0dd41a1f183b951e145f
The V2 Api should delete a non existent image

Glance V2 api initiates the deletion of an image that
got deleted during upload. This ensures that there
are no orphaned chunks of the image left behind

Fixes bug #1226013

Change-Id: I4cf5c49d2a6d2157a38467d9f7bcb20c4562b642
Remove unused import

Module exception from glance.common in
glance.tests.unit.v2.test registry api module seems to
be unused, so it's import can be safely removed.

Change-Id: Ifc201c6fb1226e556d4217898844e04069d81932
Merge "The V2 Api should delete a non existent image"
Merge "Improve test/utils.py"
Merge "Refactor glance/tests/unit/v2/test_registry_client.py"
Merge "Fix typo in config string"
Merge "Removed unsued import, HTTPError in v1/images.py."
Merge "Code dedup in glance/tests/unit/v1/test_registry_api.py"
Merge "Remove unused import"
Put formatting operation outside localisation call

Otherwise the strings will not be properly extracted
for translation.

Change-Id: I21a1c56577e7cd9fb2e31fe380b3c3bc8d1c48bf