Code dedup in test_libvirt_volume

- externed common assertions to methods
- externed common parts to setUp():
  - test disk info
  - test connector
  - test volume name, location, iqn, data, uuid
  - test user
  - test fake connection

bp nova-tests-code-duplication

Change-Id: I83bfd8b597121c9de091283845b841680e150e76
Code dedup in class ImageXMLSerializationTest

Externed common parts to setUp():
- fixture with test image data
- test image
- dictionary with test images
- test serializer
These parts were equal in the most part of the methods.

bp nova-tests-code-duplication

Change-Id: I8394c7ccbd0d71ffcf5f35c64a5c307dbf579364
Fixes wrong action comment 'lock' to 'unlock'

Change-Id: I2f285b405b598d69f80504b040b4a0e32d80020b
Merge "Code dedup in test_libvirt_volume"
Merge "Code dedup in class ImageXMLSerializationTest"
Merge "Fixes wrong action comment 'lock' to 'unlock'"
Merge remote-tracking branch 'm_src_repo/citrix-fixes' into build-temp