Fixing remaining hacking violations

The cleans up all remaining hacking violations and updates the test-
requirements to the latest approved version of hacking so we don't
regress on violations again.

Deleted several duplicated test cases (so I didn't have to fix the
hacking violations in them):

* test_secret_create_nones_blank_name_and_valid_content_type
* test_secret_get_defaults_none_as_bit_length
* test_secret_create_defaults_null_name

Change-Id: I21c7af4160c62222af0e54b947e301bc900250e6