Update add delete update member tests

*Updated add_image_member test
- Replaced ComputeIntegrationFixture with ImagesFixture
- Updated tests due to behavior, fixture and config changes
*Updated delete_image_member test
- Replaced ComputeIntegrationFixture with ImagesFixture
- Updated tests due to behavior, fixture and config changes
- Added setup class for image creation
*Updated update_image_member test
- Replaced ComputeIntegrationFixture with ImagesFixture
- Updated tests due to behavior, fixture and config changes
- Added setup class for image creation

Change-Id: I680538de3cb83e411fe763abf7cfb9365ee4fc74
Fixed rescue & rebuild server fixtures

* Fixed rebuild fixture to assign the new password to the rebuilt
server
* Added unrescue also to the rescue method in fixture, got missed out earlier
* Updated stacktach tests accordingly
* Capturing some more time attributes during server actions

Change-Id: I85ce088391a484ac15c8f20cf9ce28a920674968
Merge "Fixed rescue & rebuild server fixtures"
Merge "Update add delete update member tests"