Adds unit tests for hacking checks

Adds unit tests for Patrole hacking checks. Also cleans up
existing Patrole hacking checks for code maintainability.

This commit also modifies the P100 hacking check to work
with arbitrarily many decorators, so that rbac_rule_validation
decorator can be sandwiched between any number of decorators
in any order; the only requirement is that it appear before
each test.

Change-Id: Ic02c9278e5293311dd6f7b02790a256d391098f7
Closes-Bug: #1708794
3 files changed