Improved testcases for object-id/element-id in mock support.
Improved testcases for object-id/element-id in mock support.

Details:
- Due to issue #239, the unit testcases for the mock support
  were improved so that more non-default ID values were used,
  and the expected results were checked against the input values
  in those cases where input values existed.

Signed-off-by: Andreas Maier <38dbb04957d222ea6ce72de72413b1e55e665472@de.ibm.com>

zhmcclient/python-zhmcclient,zhmcclient/python-zhmcclient