Enable herald rule for commits that need auditing

Summary:
enable herald commit rules to have access to auditing info.

Note that the new herald condition I added contains info for the
packages. I thought about using a simpler herald condition like
"Requires audit is true or false" and let it work together with the
existing "Affected package contains any of the package". It doesn't work
because we need the info about the package to decide if the commit
requires audit, but the herald conditions work separately.

Test Plan:

• A commit requiring auditing was detected by a herald rule that checks the auditing status
• A commit not requiring auditing was not detected by a herald rule which checks auditing status, but was detected by a rule which doesn't check the auditing status

Reviewers: epriestley, nh

Reviewed By: epriestley

CC: aran, epriestley

Differential Revision: https://secure.phabricator.com/D1399