Adds test_list_XX_fields cases to list some fields

This change adds test_list_XX_fields cases to test
if listing some fields works well. A related url
example is 'v2.0/networks.json?fields=id'.

Change-Id: Ic41d83ec394b6bd7767d0523a8b21614468e0f6a
Merge "Adds test_list_XX_fields cases to list some fields"