Skip on issue for failing data driven container create test

Container create test fails for case where name is None.  Opened
launchpad bug https://bugs.launchpad.net/barbican/+bug/1354767
to report the error.  This CR adds the skip on issue for the
data driven test ddtest_create_generic_container_w_empty_or_null_name.

Also renamed the dataset item for the case where name is "None" to be
"none" rather than "null".

Change-Id: I13b7fbe979047eb598551b737e503a7a2b251a96
Merge "Skip on issue for failing data driven container create test"